The other day I took the C4 for a road trip about 200 miles. It was cold in FL- started around 40 to high of 52. Here is the engine temps I noticed on the car from the digital gauge. When moving the car was at 207 to 209 degrees. Speed between 45 to 70. When Sitting at a light depending on the light it read 212 to 219. The analog gauge just sat right above the second line and never moved.

Should be I be concern?


I am thinking a coolant change??

 

Were to begin...

I also have a 95, yesterday I drove it around town, and down a two lane highway, my outside air temp was 57°f and my [Digital] temps ran Between 182°f / 190°f

So for the given conditions, you might be running a tad Warm on the Highway...

Having said this; you need to know that you are still running in a safe temperature Zone, and you don't need to Panic!

I would Inspect the area in front of your Radiator with a flashlight as viewed through the [A/C line] opening in your fan shroud, as well as in front of the A/C coil, as viewed from down in front of the car.

 

I should of posted that in the original post. I looked at that and everything looks clear. No plastic bags or small animals living up there. Should I be looking for something else in that region or am I good?

 

Do you have any history on the car?

Has there been any cooling system maintenance done in the recent past?

How does the coolant in the recovery tank behave? i.e. rise slightly with a hot engine, and settle back down with a cold engine?

Here's the deal, there are a multitude of possibilities here; A 19 year old radiator with partly blocked cooling tubes internally, small piece's of debris lodged in the cooling fins externally, Thermostat, water pump etc. and let's not forget.. a possible leak

 

you might think flush & refill, lowwer temp thermastat(original is 195deg),and hoses. But first were your fans working. Please post year.

 

Original is 180° and LT1 specific, you can't use a standard SB Stat..

 

The car is a 95.

About ten years ago I had to replace the radiator it had a small leak on the bottom. I never messed with the thermostat that would be at the original factory set temp.

Sadly I never opened up the overfill tank when it was hot only when cool. Looks to be at the right spot on the stick. I do not smell antifreeze when I turn the car off.

the cooling fans do work. I only know this because a year ago the passenger side fan failed and needed a replacement.

 

It's a 95, so I think the stock stat is a 180 degree....I would just flush the system and refill, that should take care of it....If the car is stock, there's no reason to run anything other then the stock thermostat....WW

Your right, the LT1 stat is 180...fixed...

 

Forgive me, but that thermostat information is incorrect.

A 1995 LT1 stock thermostat is a 180 degree (ACDelco 131-100). The LT1 is a reverse flow coolant system with the thermostat mounted in the water pump, controlling the 'inflow' of radiator cooled coolant into the water-pump mixing chamber and then the engine heads followed by the block/piston areas.

This reverse flow requires the thermostat to be cooler than those for the older c4 engine (90-).

Hi Bucfantitan:,

your temps are definitely higher than they should be given the ambient temperatures and that the radiator is only 10 years old. (via digital gauge, temps should be 194-197 with analog around 185-190 -- typical difference should be around 10 degrees -- more may imply a thermostat problem).

How is the air deflector just under the radiator? If damaged or overly worn down, it could contribute to higher temps (OE replacement available via Eckler's).

How long has it been since coolant flush and changing the thermostat?

If more than 3 years, I would recommend a flush and replacement of the thermostat (recommend ONLY using the ACDelco model in title, I have found others to not work as good).

Remember to be careful of the Opti distributor, so recommend draining coolant via radiator, then flush, then again drain via the radiator. THEN remove/replace the thermostat, this way only fresh water may spill down onto the distributor.

Also examine the labeling under the hood for the correct anti-freeze, so be sure to only use it after a good flush.

If doing yourself, consider how hard your hose water is and if your water is hard (calcium) suggest after a hose flushing, use a blower into the high-mounted pressure tank (to blow out all water) and then one flush with distilled water (fill, run, drain, blowout) before final fill.

Also, recommend either buying pre-mixed or pre-mixing with distilled water.

Beware of other thermostat models from ACDelco (e.g. their 'professional model', which is actually the lower quality units -- e.g. they do not have the jiggler (which should be mounted in the up position).

Lastly, if your 'radiator cap' is older than 10 years, recommend also replacing it -- but be careful as pressure is different for LT1, so again, recommend ACDelco -- e.g. RC27


from the ACDelco website:
THERMOSTAT,ENG COOL
Part Number: 131-100
Product Notes:
Engine Cool Thermostat
180 DEG
Per Vehicle: 1; Years: 1993-1996

 

Thank you Admiral for the info.

My sticker and the book calls for the 1825-m antifreeze. I believe that is the green stuff cause that is what I have when I open the cap. I am going to do the flush get a couple of gallons of distilled water and clean the system out. I also want to replace the top rad hose. Its starting to get really soft. Plus the TB bypass is not a bad idea either since I have no coolant in the car at the time.

Now a good/nice weekend and I will be set to clean it out and let everyone know how it turns out.

 

Only if you have no clue as to how to change the antifreeze.

 

Thanks rifle coach not no clue just never done it before.

 

Hello everyone,

Its been a while and I finally had some free time to work on the coolant. I took out the old. overall it didn't look to bad. refilled and flushed with distilled water about four times. You can really see a difference from the first water flush to the last one. Came out nice and clean and clear. I was really happy with the results. replaced all of the hoses (rock auto has the best prices for the main hoses and heater hoses). Cleaned the surge and recovery tank. Installed a new thermostat. took the car for a drive. The outside temp was around 70. My digital gauge was between 197 to 207. near the end of the drive I was staying closer to the 200 mark when moving. The analog gauge stayed right above the second mark line and never moved. That was an improvement since before the flush it was closer to the third mark line.

One note for anyone who never flushed coolant before be ready for the flood gates to open when you take the knock sensors off.

Any thoughts on what I am seeing with those new engine temps? It is an improvement but not what I was hoping for. I was hoping for 180ish when moving.

 

I think its official. With the new coolant added and temps in the low 80s. I never went over 200. I think that is pretty good for a normally hot car.

Thanks

 

i'm in s flouida....mid 80's...heavy traffic/air on...barely makes 200...'170-180 on open road...160 degree t stat /fans on at 180

 

Glad you got it sorted out.

Flushing is always good, but I bet that the one biggest contributor to the improvement was the new t-stat. You said the old one was the original, and I bet by now it may not have been going fully open.

 

Did you check for debris blocking the radiator?

 

Yes everything looks clear and the front air dam is all there and nothing looks missing from it.

 

......... You have to look in between the AC condenser and the radiator ... I have to vacuum live oak leaves out of there at least once a year ..............

 

Also shoot some compressed air through them. It's amazing how much stuff can caught in between the fins on these things.