Rednels

I have been trying to solve an overheating issue for over 6 months now.

I have a C4 Race car. Its Craig Gelstons old car.

Here is what I have done so far to try and fix it.

1. Make sure there is no air in the system.
2. Thoroughly cleaned out the radiator, oil cooler, and PS coolers.
3. I used a comb to straighten any bent fins.

Im starting to run out of things to try. Before this started I could run the car all out at RA in 95* temps and the coolant never got above 195. Now its hitting 250*-260*. Whats weird is the oil temps never get above 200-210.

I have 2 questions,
1. Can a water pump work, but not be in top condition? I mean I always thought they either worked, or didn't, no in-between.

2. How big of a role does the fan play in cooling on the track. My fan is weak at best but I have always thought that on track it can't make that much of a difference, right?

Thanks for any suggestions,
Eddie

rbl

Fan at 30+ Mph is of not value. Most actually shut off.

Rednels

That's what I figured.

0Vector Vette

Eddie,
So you own the shark! I have raced against it many times. I am not saying this is your problem for sure, but I will relay my similar story. A few years back I was running a C4 as well and was chasing an overheating issue for most of a season in a car that also ran routinely at 210 degrees. I changed everything and nothing seamed to work. I pulled the radiator out, took it to a shop to be tested. Was told there was nothing wrong with the radiator. With nothing else to replace, I finaly bought a new radiator. No more problem. I had a similar problem with the C6 car last year. I changed thermostats, water pump, re routed the hoses, nothing worked. Bought a new radiator again... no more problem. I have seen first hand how tap water can ruin these aluminum radiators in very short order. The bottom half of the radiator is all clogged up but the top still flows fine. Looks good when you test it, not enough water flowing on the track. With an L98 running around 6000 rpm, you should be able to keep that car under 200 degrees. My bet is the bottom of your radiator is clogged and you need a new one.
Robert Finlayson
Performance AFX Motorsports

froggy47

but also check Rad cap pressure, thermostat, look at waterpump impellers (they can erode) depending on the material the impellers are made of.

Use an infared thermometer to shoot temps all over the radiator surface to see if there are cold/hot differentials.

Rednels

Thanks for the advice guys. I have replaced the cap, also, there is no thermostat. The Thermostat housing is there, but its been gutted, but it was always like that so I assumed that's not causing the problem.

Perhaps its just time for a new radiator. I just never imagined that would be to problem because it looks so perfect. Its a Howe and the outside looks almost perfect, but I know there is more to it that what I can see.

I just want to get this fixed so I can start driving again without worrying about the car. It really hard to concentrate on racing when you are constantly checking the gauges and short shifting trying to keep the temps down.

froggy47

Bad gauge?

Rednels

I guess that's worth checking but I think its very rare for a mechanical gauge to not work if its reading at all.

froggy47

I agree, but just throwing it out there.

It is ODD that the oil temps are so much lower than coolant, very odd.

That's what go me thinking. also the sensor can go bad.

I would not want to see you throw a new rad in & get the same temp reading, right?

Put a new sensor in b4 a rad.

Bill Dearborn

It used to be they would remove the end tanks and rod the core to get any blockages out. Have had that done many times over the last 50 years of owning cars although I haven't had to do it in at least 25 years.

Bill

Rednels

I was thinking about taking it to a radiator shop to let them clean it out. How do they remove the end tanks when they are welded on?

Woods

Oil temp seems good, Try using INFARED temperature gun on the waterpump and other parts of the cooling system. I could be just the temp sender or gauge.

dfinke23

Unfortunately you will be wasting your $$$ if you try to have it cleaned. They'll tell you it's good, you'll put it in and have the same issues.

They cannot tell if the scale is out unless they cut it apart. See below.

Buy a new one and save the headache.

sothpaw2

Robert,

Can you get scale w/dexcool/water mix per factory? Or would the scale only be significant if you run tap water+wetter? I like the idea of running distilled water +pump lube+water wetter.

TS Motorsport

Never run tap, always run distilled water and run DEI radiator relief. It drastically drops your coolant temps. We use gasoline to clean out intercoolers, I'm sure you can use the same method to clean out a radiator.

0Vector Vette

You shouldn't put tap water in even with the dexcool mix. The minerals in the water are what eats up the radiator. Always use distilled water, I add a little watter wetter for lubricant purpose, I don't believe it has any affect of consequence for lowering temps. Unfortunately, we have all been at the track, had the car run a little hot and added tap water. This is the start of the problem. You can get a Howe radiator like that for less money then it costs to go to an event and not run.
Robert

Rednels

Very good point.

Rednels

I just wanted to post a follow up.

Upon taking Robert's advice, I called Howe racing (they make my radiator) and ordered a new one. I spoke with their "radiator specialist" and told him what was happening to me and he asked if I had any motor trouble when this happened.

I explained that this started right after blowing and then fixing a head gasket. He instantly said that was the cause. He explained that the tubes have such thin walls for better cooling that when a head gasket blows your radiator cap can not vent all that pressure fast enough. The result is those tubes swell in the middle causing massive puddling to occur with the coolant and thus it doesn't flow for crap.

Once installed, the new radiator fixed all over heating issues.

I just wanted to pass this along that (just like Robert said) even though the radiator looks fine on the outside, it may not be on the inside. Best $300 spent on the car so far

Jason

drivinhard

great quote, and SO many other track related parts could be substituted for "radiator"!