An overheating problem that seems very un-common - Very Clear Description!
 

Ok, so I bought a blown up 1991 Savanna, and purchased and engine from the site here. Installed it and it have not been able to drive it for extended periods of time because it will slowly overheat, every time.

Starts cold, and slowly walks it way one degree at a time to 220-225, and I have never let it go past that. The temps have been verified by using an inferred gauge at the water pump and rad hoses.

The car over heats while driving, actually cools down while idling. (Driving at any speed, with low engine load. Beating on it speeds it up.)

The car was not stock when I bought it, I added the FMIC.

Mods -

Koyo Rad w/large fan, always running
Large FMIC
Garrett 60-1 cold side, stock hot side
Megasquirt 2 V3.0
Dual belts
Atkins Thermal Pellet Delete
Laaarge Street Ports
1600/650's
3.5" Exhaust
Still running an A/C Condenser
Stock oil cooler

The car DOES have the undertray. Widened the grill to fit FMIC.



Things I have tried

-Added stock under tray, made little to no difference. (Was not there before)
-Made sure timing was set correctly
-Changed thermostat, also tried removing it.
-Changed rad cap
-Changed belts
-Water pump looked good when I put it on the engine, spins with proper resistance and is silent. I see flow through the rad.
-Ensured thermal pellet was installed correctly.

I should also note, the car is not eating coolant, and does not bubble from the rad at start up.

Here's my set-up, and a video of it running:

I have dual belts now.
http://i294.photobucket.com/albums/m...g/IMG_1848.jpg

Idling


Thanks!!!!!

Have you verified that the fan is actually pulling air through the rad?
If it was reversed the fan would cool but then when the car gets going the forced air would make the efan stop doing it's job..and you car would heat up.

Probably not helpful but...
 

If you custom duct that cooling fan directly into that cone filter you could get ALL the hot air into your intake.

I'm just sayin' :dunno:

This to be helpful...
 

I'm betting that between the A/C condenser and the FMIC you get NO ram air help when moving. And your fan is likely not capable enough plus you have no shroud, so the fan is only moving air through about maybe 40% of the area of the radiator.


Solutions:

Put back on the belt driven fan and shroud.
Add a Taurus 2-speed fan with it's nice shroud. Start by using the high speed. If that solves it, try the low speed. You will probably need to upgrade your fan wiring to run the high speed.


Good Luck and post pics.

Lol thanks, I have plans for it, but have put all the little stuff aside to try and figure this out.


I could try a better fan, but shouldn't the car cool down a bit on the highway without a fan, naturally? Hmm...


Thanks for the replies!

Glease,

I was going to suggest checking the timing, but I see you already tried that. I ran into that issue with my 20B a few years back.

I do wonder if that FMIC isn't causing you airflow problems, especially if your condenser fins are clogged.

Alternatively, I would suggest pulling the water pump and looking at the fins to see if they are deteriorated. If they are, it may not be moving enough water under load. Just a thought.

I hope you get the issue straightened out!

No that is exactly the point- you are not getting the ram air when moving because of the FMiC and the a/ C condenser. So you do need a great fan.

If you remove the condenser and change the FMiC to TMIC you would probably do fine with that fan.

Ok awesome, I'm going to look into a larger fan. Any good recommendations?

With that inter cooler you are not getting air to rad, u need to vent the hood.

Also U NEED DUCTING to trap whatever air going to rad

2-speed Taurus fan is a good bet.

A vented hood is useful to remove air but does nothing if no air is getting in to begin with.

+1
Vented hood has nothing to do with nothing. Ducting however is VERY important.

The taurus fan is good, as are the nissan quest and 2 speed volvo fans.

Maybe the radiator is partially clogged? Had a VERY similar overheating problem which vanished when I changed the rad. Use your IR thermometer to see if the rad has equal temps at idle when running.