Trick from winder towing company in desert..put a heater coil as in stock cabin heater inline with heater line in the engine bay. It works... greatly improved ac temps when air 106 reduced engine load.

Your voltage isnt the problem you need to check spark plugs and intake vaccuum for leaks mechanical things also that's an old chevy I have felt your exact crappy idle and it's nothing to do with your fans

Jimmy, I run a severe duty fan clutch on my mechanical fan plus a GM original design pusher fan for my AC condenser. It is a factory option for the 2500 suburban/Silverado. The pusher fan works great. I just have it wired to a switch and I turn it on when my AC needs extra help. ALSO: for the rough idle, it may be that your throttle body needs to be cleaned. Mine did this before. Clean it up and it should help.

I had a similar random rough idle in drive at stop lights when hot in an older Jeep Wrangler. The fix was a vacuum leak. I tried diagnosing it with propane fed near the lines but the rpm never increased. I ended up replacing most of the Evap and vacuum lines closest to the intake. Rubber does not last forever.

7:19 in drive underload. Replace your idle air control valve.

If you installed the oil catch can on this truck , maybe it’s not tight enough and you might have a vacuum leak , cuz it does makes the car idle really rough , i hope i helped ya on this 🤞🏻

man i love your videos soo much your like the ChrisFix of GM Trucks

Here’s what I think is really causing your problem. Yes running your engine “cooler” makes sense you won’t be getting over heating issues. However, if your normal operating temp is let’s say 210 your ecu is waiting for that temperature. If it doesn’t reach said temperature it will make adjustments to timing and air fuel ratios to try and achieve the 210 degrees its programmed to. What I would do is set the probe to a normal operating temp. Usually what the thermostat opens at. I can see how running your engine cooler can cause a really wonky idle, as the engine is constantly trying to heat up and get to its normal operating temp.

Try cleaning throttle body with a good spray cleaner, toothbrush, and paper towels. Get under the butterfly valve’s edges and make sure it’s very clean.

Honestly I would install the 2nd battery and you will be good to go for life .

I have a 1999 Tahoe with factory fan and the temp is always at around 160-170

Gm designed the original fan for a reason with engineers designing. Keep it OEM

rough idle i had with mine i cleaned the mass airflow sensor and throttle body and used flue addetive cleaner and the rough ide went away. my problem was a combo of things.

Wow, you know your stuff! Disregard the negative comments, you’ll always get those who, think, they know everything.

If you want to know real temp, pick up an ALDL scan tool. I had one for my 93 Burb from 1320electronics. With it, among other things I could see actual engine temp. Dash gauge is about useless. Mine would sit at that quarter temp mark without AC, and 210 with AC in city traffic. But the scan tool showed me that the temps were much higher than 210, more like 220 at worst. That being said, my vote is back to stock fan clutch. If you want, throw in the pusher fan from the 2500s.

I’ve been waiting for the video addressing your ABS light. I think it’s time Jimmy!

I would check the A/C compressor. If the problem only happens when the A/C is on, you may have a issue with compressor “dragging”. I have seen it a few time in my years with GM and Ford.

I've got the same engine, though a year younger. And share the same common problems.. Your vehicle is old, it's an antique actually. Just like an old man, it's a bit too sensitive and it shows at idling speed. Chances are it's the fuel system and worn out cams, valves and piston rings that cause your engine to idle rough. 1) Clean mass airflow sensor 2) Add Seafoam in the tank (possibly change the gas station) 3) Stop messing around with electric system and your fans. Leave it as is. 4) Raise idle RPM to 750. I wouldn't recommend, but You may try to go as high as 900 to feel the difference. It will put some strain on transmission and take a bit more gas at city driving. 5) If you put back the clutch without a fan blade it will act as a gyroscope (a flywheel) and definitely smooth out rough idle. But your truck will loose some 🐎 🐎 and will be a little dull, the way it was before, the way it was designed.. 6) Don't forget to add high octane fuel at well known brand gas ⛽. It will definitely help with your problem 👍 Lots of luck!

I have really enjoyed watching you build this truck up. It inspired me to lift my 1990 Chevy a couple inches and focus on reliability engine wise. Love your videos, man!

I had a pair of throttle bodies on my 82 Camero. Occasionally I would spray Power Foam to clean them. NOTE: With the Z-28 running I also sprayed the carb cleaner into the small idle air motor passages DURING a rapid deceleration. This opened the idle air motor passage making it available for cleaning... worked great! I still use this decel cleaning technique on my modern vehicles.

I put this system in my truck a few years ago, I absolutely love it. Never even popped a fuse

Love your vids! I had a '97 K1500 for a very long time and just last year "upgraded" to a ''99" K2500 7.4! Found a diamond by accident in South Dakota that is clean with no rust. The tipping point for me was he had just put in a new crate motor! Even towing my boat or trailer, I can pass anything on the road but a gas station... Keep up with the great work and thanks for sharing.

maybe the vibration used to be eliminated by the clutch driven fan and that was the reason the fins were not following the star pattern, in order to counterbalance the engine vibration

I had some rough idling problems, checked everything... problem turned out to be a bad fuel regulator. Worth checking too 👌

So down to the stall issue, im in a 96, and the stall runs around 500 rpm at idle and a big upgrade is to get a higher stall converter. Now re installing the original clutch driven fan, sounds like fun but you should remember that the wiring harnesses back in those days where not adequate. Ideally you would replace all the wiring in the truck to really help your electrical issue. Overall when you blast the AC, and run the truck during a long hot day(in in NM, she still kicks while hot) you'll come to terms with a 25 year old truck struggling in comparison to a newer vehicle

Adjust it with the A/C off. The A/C requires the fans to be on.

I love your videos i have a 1999 suburban. You are awesome keep up the awesome work

Hey Jimmy, I still have the factory clutch fan on my 95 Suburban. Where you were showing the gauge is right where mine runs 350 days out of the year. I would suggest you don't rely on the dash gauge to adjust your temperature for your fans, since that is lower down on the left side of the block. The check you showed at the beginning using the handheld thermometer should be much more reliable. For an overlander rig though, yeah the clutch fan isn't a bad idea, since they really do work well. As for the rough idle, mine isn't exactly smooth when the AC kicks in either (it leaks, so that's been a while. Also, been a very cold year here, so don't actually need it.) I was wondering when you last checked your plugs? If nothing else you can check how clean the engine's been running, and it'd be one more thing checked off your list.

Use a 180 deg. thermostat, it will run great and fans will behave. My '94 K2500 Suburban has a big block engine in it so it makes a lot of heat. I use the standard GM clutch fan/shroud setup and it works great.

@1Road, I own a 96 GMC Truck. All I did was upgrade to a dual row radiator in place of the single row. I’m still using my clutch fan and the AC still blows cold at idle and in 115 degree south Texas weather. Maybe you should go back to the clutch fan and upgrade the radiator.

I really love your videos, i love the people who do the things for their own. Nice job!

The temperature at that mark right in between 100 and 210 is exactly where it's supposed to sit. I posted to an online forum with a picture of my truck's needle sitting just above that same mark thinking it was running low. Everybody, and I mean everybody who owns one of these trucks said that's exactly where their's runs - it's completely normal.

Jimmy, the bogging you're experiencing is probably the alternator at full load creating drag on the engine. That's a beast alternator and your idle should be increased up a little. No biggie.

This is exactly what i was doin last week 🤣🤣🤣 remove the e fans and go back to clutch driven fan & surprisingly everything is back to normal 😅😅 as you said , gm knows better ! 94 impalla

Thanks for the videos Jimmy. I fixed my dashboard with the L brackets and put in a new PCV valve yesterday. I have a 95 GMC 2500 with the 350 just like you. Keep the videos coming because you make it easy for me to make these fixes.

One other thing to add, I've 2 clutch fans fail on my '02 burb, 1 clutch fail on a Trailblazer and 1 fail on a Jeep TJ. I almost considered changing to electric fans on my burb for MORE reliability.

Have you made sure you don’t have a vacuum leak, when was the last time you changed the spark plugs, wires, cap and rotor

Jimmy, I have a 2wd version of your truck. 1995 Suburban, 150k miles, 2wd bone stock. I also live in hotter than Hell Texas. I purchased this vehicle 4 yrs ago mainly to tow a 23' Airstream. Love this truck. I have never experienced any problems with overheating. In fact, the temp gauge reads in the area below the 210 always. 100 degrees, pulling trailer, both a/c blowing, never overheat using the stock OEM mechanical fan and clutch. I've been watching your vids and never understood all the need, and especially the expense, to go to electric fans, new wiring, multiple alternators, etc. This 5.7 is the old TBI system. I would focus on vacuum leaks, etc on the TBI for the rough idle. Go back to OEM fan and clutch, KISS (keep it simple st.....) Love the channel, keep it up!! Peace, my friend!

By the looks of things your shevy has a carb, but correct me if I am wrong. Idling that low, just above 500, and having a alternator capable of producing over 200A with fans that is quite power hungry, drawing all that current from the alternator, will lower the engine rpm because of the alternator creating all that power. Raise the idle only a slight bit and you will see a big diffirence. Also make sure that your rubber pipes are good and throttle body is clean like it was mentioned by other of viewers. I would leave the electric fans. They are great.

I daily drive a 1999 2 door tahoe 4x4 with the original clutch fan and I put a lot of highway miles on it every day driving driving in 100°+ Texas heat with the ac on high and the temp never reaches or goes past 210. I'd say the stock fan set up is the most reliable way to go running a stock motor. As far as your hesitation goes, I don't think the fans are the issue.

Hey these trucks do this they shake a little at ideal even the one with fuel injection and the clutch fan I’m thinking it could be the spark plug or spark plug wires or the coil.

My 96 burb has the clutch fan and they have always been little lower where your was on temp, never had prob and she is at 216,000 miles still runs like a champ.

With a properly functioning thermostat, you are not going to overcool the engine by running the fans no matter what. If the engine starts to cool off too much, the thermostat will close and keep the engine at the proper temp whether the fans are running or not. Also, factory gauges are usually idiot gauges and not very accurate and pretty much just stay at the "normal" spot unless something is wrong, so I would suggest using an OBD2 scanner to see the actual coolant temp to set the fans up how you want it or installing a real temp gauge rather than going by the gauge on the dash. I hope this helps, good luck with your project!

Great Job with the electrical wire upgrade. Check you idle sensors and throttle body but I'm sure the throttle body is clean with all the maintance you do. Old hoses are like old wiring needs upgrade after 20 years lol. Check the engine and trans mounts they will cause a vibration if worn. But as many said vacuum leaks and other intake side related will cause a vibration..... GREAT GREAT video

I have the same truck,I run a 180 T-stat it made a huge difference ! I would have never went to electric fans !Stay with the fan clutch ,much more reliable !Your idle at stops is another problem probably the IAC !

hi Jimmy, i had a 92 GMC truck and i change the fan exactly the way you made but i’v install a Mechman 370 amp alternator, also i have a 300amp auxiliary battery and the truck is running great but i have doubled all the negative and positive wires , i’m also driven in middle east countries that we have mor than 120 degrees temperature in the Summer The car is running without no issues, better to check something else in your engine components. thanks a lot for your videos it is helped me a lot

Hi jimmy I think that you might have to go duel cranking battery set up as it sounds like you don't have enough amp hour's to run all your systems. Having 2 12v batteries connected to give you double the amp hours might help stop the rough idling of your vehicle. This is what overlanders do to support all the extra electrical equipment in there truck. A secondary system uses a deep cycle battery to support item's like a fridge or cooler or support lighting that is used when the vehicle is switched off.

Have you ever try turning up your idle ? I did that on my 2000 2500 Silverado after going flex a lite fans and it worked awesome never had any problems again remember is a 20 plus years truck. That might help because your alternator is making your engine work harder at a stop or a red light

I have a 1998 Suburban that I bought a little over a year ago, sort of a project truck. I noticed that my temperature gauge never went much over the first quarter mark, so I replaced the temp gauge sender with a cheap Chinese one form rockauto. Then the temp gauge went all the way to 260 after my st a couple minutes, so I knew that wasn't accurate. I replaced it again with one from NAPA, and its right back where it was before (so I know the temp gauge works!).

I have spal fans and never had a problem, i overland,tow, and use mine for oilfield work which I leave my 97 idle for days straight in hot west texas heat. I think you should look into the low oil pressure and stop worrying about your fans

Temp gauge at the first dash mark past the quarter line is normal

Oh and by the way, if your truck keeps bogging out like that. Change out the fuel filter. It's inside the frame rail on the drivers side...kinda under the rear door. Also if you can check your fuel pressure. If you have to, these fuel pumps are terrible on these trucks. Replace it with ONLY an ACdelco pump and or sending unit.

Add a second battery to run all your accessories. I've always done this for my high power consumption stereos. There is a factory bracket for a battery on the other side of the truck. It will look factory because it is factory.

you did not say if you had this problem before with the fans or the with the old alternator?? you should try bumping up the idle

Check the flex plate to torque converter bolts. They have a tendency to come loose. You will get slight vibration and eventually there will be a rattling sound when they get real loose.

The rough idle while stopped with the fans on are because of the extra strain from the upgraded mechman alternator. You should try and install a colder thermostat maybe a 180° it will help keep under hood temperatures lower which will also help your altenator. Those OBS GMT400s temp gauges aren't very accurate above or below the 210 mark. I run a 160° in my 2010 Silverado and have my fans set to come on at 203° Driving it's at 178-185 at a stop light it's at 190-203. Also Redline Waterwetter helps if your close to the cooling limit of the radiator.

I would recheck the spark plugs and plug wires, along with your cap, rotor, and coil. After that I would check to see if engine is in proper time. Doesn't hurt to check.

There's a possibility that with the slight rough idle you get on an original setup that the big alternator is pulling the engine down and excentuating a stumble while in drive and maybe even something as simple as a border line miss in the ignition system

I’d also clean the mass air flow censor, just a thought

I am leaning towards bad motor mounts, it's sounds like the symptoms, fine in neutral and runs ruff in drive because now the drive train has torque on it. Check the motor mounts. Does sound right where it was fine then started running ruff, I don't think it's an electronic fan issue with load on alternator. I have the exact same set up you do, dual flex-a-lite fans, 250 amp mechman alternator and had it for a couple years and it runs smoothly. Had to replace the fan motors but that's it. I live in AZ where it gets 120° in the summer and it works great

I was thinking of installing electric fans for my truck and my wife's truck. But I don't want to have any issues. I was thinking the same as you. As far as going with the fan clutch and maybe a small electric fan to help for cooling. Just today her water pump gave out. I'm going to have to replace that. I already watched your water pump replacement video. And we both have a super wicked sound system so we have to upgrade our alternator. Also I was going to install a second battery.

Jimmy! Is your Idle Air Control valve working properly? It should make the rpm raise a little to compensate for the alternator load and AC load. That truck never had electric fans so it also might not be compensating for the load on the fans.

I really enjoy your video .. To maintain torque during hauling and load for this type of trucks because it is designed for this purpose, I don't expect an electric fan to be a suitable replacement for a factory fan, Through my research to upgrade this type of t b i engine I found 3 things to improve Long tube headers, Intake with performance air filter .. I just finished worked on my truck tahoe 95 and the change was very clear with the original fan.

idle air control valves go bad too happened to my 90 chevy has a clutch fan and one day randomly started idling poorly wouldnt really want to go from a stop but once i got it going it would drive sorta normal... maintenance is key to keeping everything working properly on the newer vehicles you have to worry about the computers being damaged when you're giving someone a jump start

There must be an issue with the flex-a-lite fan mechanism I would take it off and add a controller with relays. I used a controller from Davis Craig and it works really well. also try changing to a 3 row radiator with the e fans it might make things even cooler.

I agree with Adam replace your IAC Idle air control valve or your EGR

maybe vibration is coming from the engine due to old engine mount bushing. my old hilux would vibrate at idel i changed it and it went away

That oil pressure seems a little low. Mine is at 40 idling at normal engine temp

Please use the OBDII to check the temp... These gauges are know to go out at about 10 to 15 years.

I would be trying to diagnose the rough idle. Its in your engine. Clean your intake manifold and upgrade from the old school poppet valve injector system to the updated ACDelco mpfi system. Your idle and low end torque will be worlds better. Did that on my suburban at 280,000 miles and ill expect to get many more miles on her.

After watching 4 of your video from a year ago. I was like, I'mma follow this guy so just in case ik what to do with my 04 Dodge Durango 🤦‍♂️🤣

Clean MAF sensor ASAP. Clean TBI next. Replace fuel filter. Replace air filter. Distributor cap and rotor as well cause moisture in cap can be an issue.

You need to replace your temp sensor switch that controlls your gauge in your truck! I have a 98 with electric fans and I thought they were so great because my temp stayed down in 160 area. If you hook up an obd2 reader with the torque pro app it will tell you your exact temp the the ECU is reading. READ YOUR TEMP WITH AN OBD2 READER! REPLACE TEMP SENSOR SWITCH!

My 95 pickup with original fan and live in az with 115 Temps sits at the exact same temp about 190. I prefer lower because when I'm towing up hill and I start to heat up I know i have room before I fully overheat instead of going straight to overheat. It sounds like a vacuum leak as far as rough idle. My brake booster went bad

I have a 1999 Tahoe, sold new in California with the Police Package which has HD Cooling. It had 100,000 miles when the a head cracked in 2017 so I bought a new crate engine, 350 Vortec same as was in from factory, from Scoggin Dickey in Texas. Cause the engine was out I yanked the radiator and took to a Rad Shop where they flushed and cleaned it. The other day I went on a 300 mile round trip in 95 degree weather and driving at 75 MPH all day in that heat my temp gauge showed right around 160. Yes GM knew what they were doing and if you haven't already done it take your rad and have it flushed and put the stock fan on and you'll probably see a difference in how hot/cool your Burb runs. Reading through the posts and people talking about a 2nd battery my Tahoe has 2 batterys from factory.

I live in Arizona in the summer its like 85-120 degrees my truck runs at 190-200 degrees and in the winter when its 38-70 digress it runs at 160-180 because its cool outside

You'll want to adjust the temp with the AC off. If it idles fine with the AC off you could be experiencing the beginning of a compressor failure.

If you sale those fans please keep me in mind . But put 2 big batteries in the truck and also these trucks the cap and rotor a small crack can cause dumb issues I would check that as well

Definitely sounds like an air or fuel delivery issue to me. But could also be ignition related...i.e. bad plug, plug wire, cracked distributor cap etc.. it does not sound like a volt drop or amperage issue.

You have other issues. Voltage should be 14.4. You either have a vacuum leak, bad IAC, bad wires or distributor cap/rotor. Those fans are working fine, just make sure they turn on around 200 degrees and that your thermostat works.

Have you done a "voltage drop" test on all connections and cables.

I've been burning through the videos about this truck for the past few weeks, since buying a 95 K2500 Suburban. You've been doing a lot of the same things I have on my modification/repair list (the hinge pins were the first video I stumbled on), so it's been great to see how things are working out. This issue really is crazy...it seems like it would be more helpful to have a MORE variable speed controller...the presets just don't seem to be cutting it. But I wanted to pass on this tip: the factory service manuals have a TON of information, like idle speed spec in P or D, the effect the AC should have on idle, and of course so much else. These are just the things I think would've been helpful while trying to figure out this mystery. Anyway, you can find them on the gmt400 dot com message board; these manuals have definitely helped me in tracking down a crazy cold idle problem.

My suburban rests at the same temperature. That’s the normal correct temp before you started your adjustments. You should put it back. I’ve owned two suburban of that style. When you start your car this could cause some serious problems in an area that doesn’t accommodate repairs.

You may not need the 250 amp alternator with the factory clutch fan. Might be good to reinstall the 140 amp alternator from power master again

My 99 k1500 Burb used to sit at about 160 constantly, Checked the Engine Temp on my scan tool- and was running roughly 195- where it should be. So I know it wasnt the Coolant temp sensor. That was properly giving the PCM the correct signal. and then i changed the Temperature sending unit- The one that sends the signal to the instrament cluster gauge (NOT the Coolant temperature sensor). Problem went away and idle got better in Drive, plus it feels like it shifts better.

Put a switch on one fan or have it only come on when the temp reaches 205 or 210. The old third gen Camaro z28's with a 350 had dual fans. Only one can on with temp raise and the second with the a/c. The first fan came on around 210 and cut off at 195. Try disconnecting one fan just to see if it makes a difference.

Add second battery will fix your problems you can get battery tray for diesel so it will look factory

I love your videos. Keep the good work going.

i have a 2000 tahoe z71 5.7L and i got a d3100 connected to a mechman 370a alternator, voltage is 15 and change on a cold start and never goes below 13 on hot days. had a rough idle also even with that power plant, did a simple tune up, cables plugs fluids, air filter, shes smooth as my balls after a clean shave. i recommend doing a full tune up brosky

i have a 1988 k5 blazer, i got a fan off a suburban that mounts in between the grill and the a/c radiator, hooks up to the wiring that comes to the compressor so when you turn the a/c on it comes on, as the compressor shuts off it also turns off, found it at a junk yard in a suburban, looks like you have the newer set up, but should be identical to mine until 1994, and 95 changed but i think the a/c is the same. hope it helps.

I used a big block rad (454) and factory mechanical fan and never had an issue. But I live on the east coast and may not have the temps u see on the west coast

It'll be REALLY interesting to see if swapping back to OEM fan fixes the issue. My Dad has a '95 and has been complaining of the idle ever since my brother put a wrench to something (anything, he could have just checked the oil and Dad would've blamed him!! 🤣)

I never had that problem i just put some 2005 gm fans and the original wiring work good I use my yukon off road only

Look up about the idle speed screw hidden in the TBI. It's hidden behind a bronze pointed cap that has to be drilled through to access the factory set idle speed adjustment screw. Stock idle is 700-750 bump it up 50 rpms and reset IAC valve too? ( not sure if IAC valve will help but it's normally mentioned with idle adjustment.) Try another 50 rpms and see if it still happens, I wouldn't go crazy as it's not good for mpg. Probably will solve the rough running and couldn't hurt to torque converter intake manifold and check for vacuum leaks. your cooking your engine set variable speed controller to 195° like thermostat because anything less is waste and taxes alternator and reduces fuel efficiency. engine was designed to run at 195 so set the controller to match it. Another thing to look at is upgrading ac motor wiring or cleaning rotor and stator like you did with your power window motor. Also excellent time to spray coil cleaner on indoor evap coil and clean while you have access with fan out. It will definitely make a difference in cooler air, and might freshen up the car too. Unfortunately later on GM added a cabin air filter to protect inside coil from dirt and stuff but that isn't you're vehicle. Make sure to rinse coil cleaner off with water and run the ac afterwards when put back together which causes condensation to rinse any areas you may have missed. Corrosive coil cleaner isn't best left on coils for extended periods. BTW have you already pulled drive shaft and regreased the axle splines?

I'm thinking it is not the fans or temp. I would check the following:. 1) vacuum lines, 2) spark plugs / spark plug wires, 3) throttle body clean 4) MAF sensor 5) EGR valve.

Put the clutch fan back on or add a 2nd battery. Your alternator is bogging down trying to run the fans and charge the battery. Why not keep it stock but add a small aux fan with just a manual switch? Then if it starts to get a bit hot just flick it on.

but then think of this too when it's hot out some times the fans will try to keep the truck cool

Have you checked/cleaned the IAC? I'm not familiar enough with the 5.7TBI to know if there is an AC Kick function on the IAC to slightly raise the idle speed when the AC compressor is running.

I have 2 batteries in 1999 Chevy Tahoe. One powers engine, other powers auxiliary dash etc.

Hey 1road there’s a lot of fire danger in California you better watch your back