overheating new 86 burban 350

[burbandog]

I just put a new5.7 350ci engine in my 86 suburban, according to my stock temp gage i am running about 220 degrees, obviouslly too hot! i put a new "stat, waterpump, radiator etc in it and it still runs hot, what should i do next? The timing is set right too!

[Pamsdad]

Reverse rotation water pump(serpentine belt)?

Inaccurate gauge? Bad radiator cap?

Running lean?

Need more info...

[burbandog]

how do i find out if it is running lean?
New radiator cap,
Standard v- belt drive
Ive been told to switch to a mechanical therm gage, as the stock one may not be accurate

[Pamsdad]

Regardless of what some people say, you should run a 195* thermostat in your vehicle. Better fuel economy, thermal efficiency, etc. This can only be done with a properly working cooling system. Don't overlook the simple/obvious solution.

Most times, factory gauges are inaccurate. Best check with known good mechanical gauge.

There are a few ways to check for lean condition.

If it is horribly lean, it will sputter and hesitate on acceleration.

Engine will ping with high octane fuel.

Reading spark plugs after driving.

Monitor EGT(Exhaust Gas Temperature).

[burbandog]

Thank you sooooo much!
It is sputtering when i try to accelerate when it is cold, i do have a 195* stat, how do i monitor the EGT???
Again thank you

[Pamsdad]

I never said sputter and hesitate when COLD.

Now you may have an incorrectly adjusted choke. This is a carbureted engine, right?

Monitoring the EGT means you will have to put a thermocouple in the exhaust manifold and read it while driving. I didn't mean this one seriously. EGT is normally monitored on Racecars of all kinds and Turbo cars/trucks.

If your Sub is carbureted, Rebuild it(fairly easy), or borrow a known good one.

[burbandog]

fixing the a/f mixture seems to have hepled, the carb, manifold everything on the engine is brand new!
Thanks again

[papiichuulo]

Originally Posted by Pamsdad

I never said sputter and hesitate when COLD.

Now you may have an incorrectly adjusted choke. This is a carbureted engine, right?

Monitoring the EGT means you will have to put a thermocouple in the exhaust manifold and read it while driving. I didn't mean this one seriously. EGT is normally monitored on Racecars of all kinds and Turbo cars/trucks.

If your Sub is carbureted, Rebuild it(fairly easy), or borrow a known good one.

Ok, so this isnt a 'burban with a 350cu. but a CK w/ a 305cu. that I am being asked to work on. In the mornings, when the engine is nice and cold, it sputters and hesitates, (the 5-spd just magnifies the "bucking", hehe). Once it warms up, it doesnt do it as much, runs pretty good actually but still a little weak. No carb. here tho, throttle body (T.B.I.). You think it could be a mixture and/or choke problem??

[2000CAYukon]

Originally Posted by papiichuulo

Ok, so this isnt a 'burban with a 350cu. but a CK w/ a 305cu. that I am being asked to work on. In the mornings, when the engine is nice and cold, it sputters and hesitates, (the 5-spd just magnifies the "bucking", hehe). Once it warms up, it doesnt do it as much, runs pretty good actually but still a little weak. No carb. here tho, throttle body (T.B.I.). You think it could be a mixture and/or choke problem??

You should really start a new thread. There is no choke on a TBI. The ECM controlls fuel based on Engine Temp. In your case the temp sensor for the ECM (in the intake) could be bad and reporting the wrong temp and you get hesitation when cold.

//2000CAYukon