Hi Temp

BRONCO · 01-07-03, 04:17 PM

Hi folks.
Ever since I bought my 96 LT4 in August of 2002, I've noticed that the operating temperature gets pretty high in stop and go traffic (between 202 and 212 and sometimes even higher). If any of you are familiar with the 405 freeway in southern Ca. , this is the freeway in question. The car has never gotten so hot that it boils over or even steams. As long as the car is moving, there is no problem. I took it to a repair shop and was told that I needed a water pump. I put in a new water pump and under normal driving conditions I've noticed the operating temperature is lower than before but in stop and go traffic the temperature get up there again.
Has anyone out there with an LT4 GS CE. had a similar experience? The engine has 78033 miles on it.
I would appreciate any help anyone can offer.
Thanks

lt4 gs · 01-07-03, 04:40 PM

Welcome.......and sorry to have to say this: but, you got hosed on the water pump, I believe. Based on what you are telling us.....the temp range with a stock stat is well within the normal range. If you put a 160 or 170 degree stat in and a cooling fan switch to turn on the fans earlier your temps will drop to around 180-200 depending on all the variables of the daily wx and the time sitting in stop and go.......I run a 160 with a fan switch that comes on earlier as well. I can still see 210 on a real hot day w/ a lot of sitting....as for the pump......talk to your local ag/news station/bbb. Also, do you have the old alledged faulty pump?

mac96 · 01-07-03, 08:18 PM

Hi Bronco. I think you should find a new mechanic. From what I.ve learned in this forum and from driving my LT4, the temps run high. Normal driving on a 65 degree day, my temps will run 180 to 195. But stop and go in heavy traffic will drive it up to 220 to 230. And I start getting nervous. This summer, I'm going to do what many have suggested. Get a 160 degree thermostat, and maybe get my aux fan to turn on at 180. I'm sure you have checked your coolant, but I also crawled under the front with a high pressure air gun a cleaned off the radiator coils. Leaves and trash tend to wedge up there. Hope this helps.

BRONCO · 01-08-03, 11:23 AM

Thanks guys for all of your help. I did use a high pressure air gun to clean off the radiator coils "mac96" and also checked the coolant. Along with the new water pump (which I probably didn't need "lt4 gs") it did bring the temperature down a bit. But as mentioned before, that stop and go traffic tends to bring the temps back up.
I get that nervous feeling also, just as you did, when I see that temperature guage go up there. Now that I have a new water pump and the radiator seem to be fine, I will do as you suggested "mac96" regarding the thermostat and aux fan.
I will let you know the results.
Thanks again for you help.

CKA_Racing · 01-09-03, 07:37 PM

Actually, I'm amazed that you did not have any issues with the pump at all considering you have 78,000 miles. These pumps normally don't last that long. It may have had a very small leak from the bearing/weep hole area. That's very hard to see and smell. You would be able to tell from looking at the old pump. So, it may in fact needed to be replace but not for the suppose over heating issue. Well , at least you have a new pump and you won't have to experience what other's have. Badly leaking water pump that may damage your opti. I know the 96 has updated opti. But that won't help if the opti seal is leaking and a boat load of anitfreeze falls on it. That may or may not cause damage. I would not want to find out.

01-10-03, 01:12 AM

I understand that the LT4 is made to run hot for emissions. I don't think the 2nd fan hits full stride until 228 degrees. I just bought a 160 stat and my rad coils are clean so I will need a reprogram of the fan temps and will be running cooler. Iv'e seen 232 on mine, and want the cooler temps for performance.

Denny Nelson · 01-11-03, 11:02 AM

I thought I saw some mention of a product "Water Wetter" in this dicussion. Last time I was at my favorite Auto Parts Store I picked up a container. $7.95 as I remember. Sounds promising. I am going to flush and install just enough antifreeze to protect against +10 degrees. I am in the foothills of No Cal and we rarely get below +20. This product will then perform even better at the other end of the thermometer. Has anyone tried it? I had the same problem as Bronco and will address it in Spring. Denny Nelson

01-11-03, 02:51 PM

I am curently driving the same route, 405 Fwy. over the Supulveda Pass, the temp's your seeing are normal for stock LT4. IMO I would look for a new mechanic :blow

See you on the road

Mike

Rowdy1 · 01-11-03, 03:22 PM

There's been a number of posts on this and other similar products. It seems to be a matter of opinion as I didn't do a search for the old posts. I personally use it but I use three bottles of it. I had problems with my engine but it's no where near stock and the older vettes were known to run hotter because of the design and positioning of the radiator. I can't say by itself made a difference as I changed my stat, my fan, went to a BCool aluminum radiator and added an elctric fan also though I never use it even in the hottest temps. I've done a few parades in July & August and never had a problem since.

No Go · 01-16-03, 04:55 AM

Your Corvette is operating as advertised.

Just because you "see" a number that seems high, it is what they designed it.

Remember the car doesn't have anything that pushes/pulls air thru the radiator while stopped, until the fan comes on...at ~227 degrees.

No Worries!

BRONCO · 01-16-03, 11:22 AM

Thanks a lot to all of you that responded to my hi temp problem.
Actually you have all assured me that the high temps in stop and go traffic are rather normal for this car as long as all components of the cooling system are functioning properly. Although I did pay the price for a new water pump, which I probably didn't need, I feel a lot better knowing that at least the water pump shouldn't be a problem for a few years.
Other than that, I am enjoying driving my LT4 everyday.
See ya on the road.
Bronco

twiget · 01-16-03, 08:39 PM

I'm not sure why this thread was closed, but I see no reason for it to be. So I'm going to reopen it.

I also merged your newer Hi Temp thread with this one Bronco.

And Bronco, dont worry, like everyone said, your 'Vette seems to be working as designed.

Jason

Wamp · 01-29-03, 09:10 AM

I was thinking that a cooler engine runs better with more power. After reading forum posts it was my conclusion to go ahead and change out thermostate and reprogram fans to come on earlier. I understand that the LT4 runs hot. I talked with some people that know alot more than I do about cars and was told that the factory setup on these cars is optimal. That the higher temp opens up the emmisions and lets the car run better and with less gas. If you mess with the temp then the emmission cycle will not start. Any fact to this? At what temp does this cycle start, anyone know?

04-06-03, 11:54 PM

Gentlemen:

Thanks for the great input on LT-4 engine operating temperature ranges. I've had my 1996 LT-4 since late July 1995; ordered the car while I was stationed overseas and picked it up when I returned to the states. Damn, I still love driving this car.

Last month, I noticed an "add coolant" warning message, which prompted me to bring my car to a local Corvette repair shop. Since then, I have been watching the temperature gauge routinely, noting temperature differentials and associated driving conditions.

Bottom Line: your input is consistent with my data.

Thanks again.

Tony

froggy47 · 04-17-03, 08:38 PM

Also remember, turning the a/c on is supposed to turn on at least one fan, not matter what the temp is.