89 RS with a L98 in it. This bastard car has had overheating problems since the TPI went in.

Large custom radiator with 2 fans rated at 1250cfms each with a shroud. They are wired to run when the engine is on.
160* thermostat
Stock Waterpump
Stock Pulleys
Transmission cooler
Timing is too far advanced. I think my balancer's mark is off. It pulls timing at all RPM's.

Car runs good, plenty of power, with AC off it stays at 180*. When I start moving and the car is under 40mph it starts getting up to 190*. After 40 is cools off dramatically.

With the AC on, it goes to 195* and when moving it climbs to 230*. Being in florida, I have to have the AC. I am losing my mind with this car. I replaced the headgaskets last week and my heads were warped. But its still overheating. Is my waterpump becoming a problem? This is a street/strip car that will not make it to the strip!!! I was wanting to go with a electric, but I will use a mechanical pump if the damn thing will cool the car!

Ideas???

 

I was thinking about a Stewart Warner stage 2 and a electric pump inline with it. Thoughts?

 

I would fix your timing before you go any further.

 

I definitly agree that you need to address the timing problem or you'll have un-deeded holes in your pistons.Are you hearing pre-ignition(spark knocking)when driving?I take it you aren't using knock sensors.Also has the ECM program be modified?
When you're moving above 40-45mph the lower airdam provides the majority of the airflow over the radiator/condensor.When you say stock water pump how old is it?You may want to go with a Flow Cooler pump instead of an electric pump for a street car that goes to the track.

 

I agree the timing problem needs to be fixed first. Do you have a air dam on the car? That is the main reason for overheating at a cruise speed. Was the block been rebuilt lately? I ask this because the machine shop that preped one of my blocks put the wrong freeze plugs in and it caused overheating

 

Ive tried. I set my timing to 0 on the balancer and the car is pulling 20* of timing according to the knock sensor. I think my balancer is screwed. Granted, the car is pulling like a mother.

I am gathering this data on a snap-on scanner I have at work. I retarded the timing bit by bit until it only pulled 1* but it lost all of its power. Again what was weird is after adjusting it, I pull it into my shop and it starts pulling timing when I free-rev it. I am wondering if I also have a faulty knock sensor or the engine is throwing false knock.

The chip is bone stock. A/F ratio seems to be alright, but I do not know for sure. The headers are 550*-600* range. Maybe I should bump the AFPR up 1-2psi...

The waterpump is old in time, but not mileage. Its been around for 4 years, but it hasnt been on the car in 2. In those 4 years I probably have put 5,000 miles on it.

I do not hear pinging when I drive it, which again leads me to wonder if I have a bad knock sensor or false knock coming from somewhere. You would think you would hear 20* worth.

Over 40 its fine. Its during idle and for the most part when driving slow. The symptoms match a cooling fan efficiency problem, but the damn things feel like theyre going to pull your hand through the radiator when you put your hand on the other side.
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I hate double posting, but yes I have a air dam. When I put the larger radiator in, it was taller. So I had to cut the bottom off of the radiator support and lower it 1". I cut 1" off of the air dam. Just for clarifications, the issue is below 40, not above.

 

is your engine advancing the timing while you're timing it? like if you twist the linkage on the throttle body while you've got the timing light on it, does the mark move? also, what does the sticker on the underside of your hood say? 0' or 6' ?

 

Didnt check that. I undid the connector to disconnect the spark control.

Its a swapped car. Stock on my stock engine was 0*. Since its a L98 it should be 6*. I have it in the right area now, but I got to figure out why I cannot see the mark very well.

 

I know this may sound dumb because you stated the motor pulls strong but could the distributor be 180 degrees out?Just a thought because I've worked on cars with similar symptoms and that was the problem.But again they also didn't have much power either.

 

Thats definately not it. Every 180 I have seen/done has always backfired hardcore.

 

Double post - sorry.

 

You have a point on the distributor but it doesn't always happen.On the cooling system was it purged to prevent air pockets that could cause cavitation and hot spots.Also are you using a shop scanner or a portable one on the road to monitor temp and timing?Just trying different trouble shooting flows to pinpoint your problem.

 

Portable and on the road.

 

Found the problem, I think.

When I pulled the valve cover to adjust the valves, out of the bolt hole for one of the valve cover bolts, there was coolant pouring out of it. Cracked head.

Well, time to bite the bullet and install the AFR's.

 

its interesting that it occurs below 40 as thats when your cooling fans are on.. 40 is the cut off.. and a water pump that sits around without coolant in it for 2 years.. good chance of rusting.. i do have to say.. i just drove an hour and a half drive in nj in about 80 degrees with a/c on and i too ran 230.. its been thats just the way these cars are.. i am also researching the stewart high flow pumps.. let me know if u hear good or bada things about them

 

Check your air dam, under the radiator. People commonly toss them, and that is usually the culprit.

My 350 GTA, with dual fans, and a stock temp thermostat, pretty much never gets over 200 degrees, and that is here in central Texas.

 

yea i have the air dam.. its wierd i had the motor put in with a new pump.. then the pump took a crap like 8 months later.. so i got another factory pump.. nd thats when it started running hot.. b4 that it ran 195 on the dot