LS-coupe cooling saga continues :(

[greenbullitt]

Any updates? What's your next step?

I worked on it with James fr a bit tonight. I pulled a vacuum on the cooling system and refilled, no dice. Its still hot. HOWEVER, at 200* on the gauge, it didnt look like anything was moving through the radiator core. I really think it has a pump issue.

[greenbullitt]

btw James, If you want to try that pump of mine, you still can.

[dville_gt]

btw James, If you want to try that pump of mine, you still can.

If you don't mind pulling it off I'll swing by and grab it. Wouldn't hurt to know before I put my order through for a new one.

[stevo]

Your fans behind the radiator are pulling, not pushing, right?

A friend bought a 95 gt that had a cooling issue as speed, not so bad idling, and asked me to look at it. Someone had put an aftermarket fan in it, and wired it backwards. Made me giggle.

Stevo

[kingjason]

When i was just a young lad I had a lifted 90 Blazer that was pretty sweet. When I put a new belt on it I decided I wanted a snazzy looking flex fan. Rode my moto for the next month or so and didnt think anything about it. Started driving the truck and for the life of me couldnt figure out why on the highway it ran cool but got hot fast at lights. Who would have thought my truck needed a reverse rotation fan. I can not remember who caught it but someone was standing in front of my truck and asked "hey why the hell is your truck pushing air out thru the radiator?" . lol

[Big A]

If you don't mind pulling it off I'll swing by and grab it. Wouldn't hurt to know before I put my order through for a new one.

It seems that all bases have been covered, except for the pump, and the uncovered ends of the radiator, and I can't believe that the "10%" of the radiator that isn't covered is the problem. Hopefully the waterpump is the problem and you can move on.

[dville_gt]

It seems that all bases have been covered, except for the pump, and the uncovered ends of the radiator, and I can't believe that the "10%" of the radiator that isn't covered is the problem. Hopefully the waterpump is the problem and you can move on.

I hope the pump solves it, I know greenbullitt chimed in about it, but there was very little activity that you could see in the "turn around" tank of the radiator (double pass radiator, cap is on the tank that has no inlet/outlet), so maybe this will lead us to the answer.

I just can't find ANY post on ls1tech or any other sites where people have had a pump go bad like this.

[Lason]

I thought about this deal the other day on the way home from work. Had both A/C's going full blast and was sitting in traffic in my suburban and looked down and my temp gauge was inching up higher than I have ever seen it. It had to gotten up to 220 or so. When traffic cleared up a bit I goosed the throttle a bit and the damn thing just shot up to like 230-240! After I got moving a bit it came back down to 200-210 where it normally sits though. Its a 5.3 LS motor btw with the stock shroud still on it and I have replaced the mechancal fan with 2 16" fans. This weather is not the weather I would be using as a baseline on engine temps, its been crazy hot but I know you know that.

[dville_gt]

I thought about this deal the other day on the way home from work. Had both A/C's going full blast and was sitting in traffic in my suburban and looked down and my temp gauge was inching up higher than I have ever seen it. It had to gotten up to 220 or so. When traffic cleared up a bit I goosed the throttle a bit and the damn thing just shot up to like 230-240! After I got moving a bit it came back down to 200-210 where it normally sits though. Its a 5.3 LS motor btw with the stock shroud still on it and I have replaced the mechancal fan with 2 16" fans. This weather is not the weather I would be using as a baseline on engine temps, its been crazy hot but I know you know that.

Last night we went out in it and it was only about 88* at that point, a/c on, driving pretty moderate, then brought it back and let it idle, got up to 225* and couldn't seem to cool at all from there. Drove it home no a/c and it ran 199* stop light to stop light. Turned on the a/c a mile or two from home and by the time I was at the house it got to about 208*.

I built shrouding for the radiator (to seal the engine bay from the area in front) and an air dam for the front. Might have made some difference, but not nearly enough.

Lason, have you ever heard of a stock pump having impeller erosion or cavitation problems?

[shumpertdavid]

Last night we went out in it and it was only about 88* at that point, a/c on, driving pretty moderate, then brought it back and let it idle, got up to 225* and couldn't seem to cool at all from there. Drove it home no a/c and it ran 199* stop light to stop light. Turned on the a/c a mile or two from home and by the time I was at the house it got to about 208*

This all looks pretty normal from what I see day to day here at work with cars running in the bay to highway test drives. Have you considered going to a 160 t-stat like hypertech offers

[Lason]

I have never heard of stock pump problems personally. Only real overheating problems I have ever heard about with LS motors was usually due to people blocking off the steam ports along the top but you had them run into the water pump which is how I had them on my Datsun with no problems untill I went with a remote electric pump and then I ran them straight to the radiator. Damn motor wouldnt warm up at that point and that is how I popped the motor! 32* night and it would never get over 100* and spun a bearing.

That being said I have seen some weird crap with stock LS cooling systems. A buddy called me one time and said his 98 camaro was overheating and we popped the radiator cap and there was some brown sludge in there that looked like chocolate cake. Went probably half way down the radiator too! We flushed the hell out of that thing and it ran like a champ after. I think it had to do mixing antifreezes or some crap like that.

[Txstang1]

This all looks pretty normal from what I see day to day here at work with cars running in the bay to highway test drives. Have you considered going to a 160 t-stat like hypertech offers

I agree on that being close to normal. My carb stroker runs the same temps with ac on/off. ITs just that fucking hot outside.

[2165 Turbo Rail]

I don't think it has anything to do with the temps under the hood. Remember I have the same radiator. in front of the radiator is the big intercooler, big tranny cooler, big AC condensor, the Windstar minivan fans... but I also have the turbo making tons of heat and I have innerfenders still and my car doesn't get hot at all. I sure hope you get it figured out soon

[dville_gt]

I agree on that being close to normal. My carb stroker runs the same temps with ac on/off. ITs just that fucking hot outside.

I can see how most would think this sounds normal, but the numbers I just posted were @ 88* ambient, not 105-110*. The car with a big double pass radiator and fans on should be able to at least maintain under 220 in 88 degree air at night (after a fairly modest drive around the neighborhood), right?

[dville_gt]

Oh, and the shrouding seems to be working, I have never felt so much hot air flowing out from the cowl vent like it should