My thermostat housing was leaking so I changed it out, it had a 160 in it and ran about 200 to 220, Ihad a new 180 put it in knowing that it should not change the temperature the engine wants to run but seems to be running about 20 degrees hotter, doesent make any sense to me is this somewhat normal or should I put the 160 back in? Thanks in advance James.

 

the 180 thermostat is really want you want. Not sure what year you have but I have a 79 and this is what I did to cool mine down. Bought a new water pump, new radiator, new thermostat and hoses and still had the hot car problem.....My car was missing the front air damn that goes under the radiator and funnels air up that way. Put that on and it dropped my temps about 20 degrees going down the road.

Another item that will raise your temp is if the timing is off. That will really cause your temps to go up.

Put more information in here about your car and you will get all kinds of help in the next day or two guaranteed!

http://willcoxcorvette.com/product_i...ducts_id=23649

 

Well, one can argue about 'what thermostat you want', but the more important question is "Why is your car running at 200+ degrees?" A stock Chevy engine will run around 180 (or so), unless it has a higher temp thermostat in it. Since yours runs hotter than your thermostat, there is something 'amiss' with your cooling system. It could be many things: radiator clogged or limed up, bad water pump, collapsing lower radiator hose, missing radiator shroud and/or seals, defective thermostatic fan, etc, etc. The thermostat is also a potential problem item, but you changed that and it got worse. At this point, you would be better off with NO thermostat--as that would result in the lowest engine operating temperature your engine/cooling system (in its present state) could maintain.

 

Use an infrared thermometer on your thermostat housing to try to determine if the engine is really that hot. Could be a bad sending unit. If you have an instant digital meat thermometer you can also use that and get a reading within a few degrees of the actual water temp also. Just hold it on the thermostat housing for a min.

Advice above on air dam, fan shroud, etc. is good if there is a heat problem.

 

May I offer a different approach: Completely omitting the t-stat often does not allow for a cooler engine. The t-stat actually keeps water in the radiator long enough to cool it down. The T-stat is supposed to open, let it out, and close when the cooler water from the radiator gets in. Id check what was stated above, go thru everything else first before playing with factory settings. My BB is also currently running hot, and when I get a chance to look at it the first thing Im looking for are all my air dams and getting the proper fan and clutch.

7T1-No offense or insolence intended.

 

Your 160 may have been a high flow stat.

 

Check your guage .

Bill

 

Great info guys, was wondering if where the sending unit is located would give me a higher reading. I,ve got the old camel hump heads and they had no place for the sending unit so it is presently on the intake. Everything else is in place shroud , new high flow waterpump etc.

 

By the way I was told that those old camel hump heads will run a little hotter because there high compression,and if I went with a good set of aluminum heads they would help the motor run cooler.Any thoughts on this?

 

My suggestion would be to find and fix the issue you have FIRST, then think about modifications. Something in your cooling system is clearly broken - it SHOULD have no problem keeping the temp down.

 

Do you the location of the temp. sending unit being on the intake insted of the head would make any difference?

 

When you say 'on the intake', are you actually talking about on the thermostat housing, or somewhere actually on the intake? And if so - where?

Also, when are you getting these readings? When idleing? In traffic? On the highway? In all the above cases?

Did you put in a new sender, or did you move the stock one? Aftermarket senders are not always calibrated to the stock gauge, so if you replaced the sender and are using a stock gauge, that could be the issue. If you replaced the sender, try hooking it up to matching (new) gauge, and see what you get.

 

The temp. sending unit is now almost right beside the thermostat housing.It is a new sending unit,the one before it was not calibrated properly so it was barley showing any reading.This one is and with those camel hump heads there is no place to put the unit like there is with the stock heads.Once I got it all together I let her warm up, took her for a ride and the temp pretty well was consistant.Could I have gotten an air lock in there? Thanx in advance J.S.H.

 

Before getting too deep into the issue, I would suggest taking a look at the basics. I have read so many posts about how hot these cars run, but people are only focusing on the engine.

The C3, due to it's nose is a bottom feeder of sorts, with most of the cooling air needing to be drawn in from under the front. I once read an article about the story behind it's original release in which they could not get the big blocks to cool adequately. Duntov was in the hospital for a portion of the development, but on some press day, they still had not solved the problem. Duntov shows up with a jigsaw and cuts three holes in the lower front fascia to allow more air to be drawn in, and that's why the three holes exist. Airflow is critical to temperature management.

I would suggest going back to the basics here. (much of this is referenced by 7T1vette above, but it is worth emphasizing)

As a poster above has mentioned, check your chin spoiler, it is critical. If you don't have one, get one and put it back.

Getting the air to the radiator is one thing, but forcing it through is quite another. Check to make sure that ALL of the required foam seals are present and doing what they are supposed to do. Remember, our radiators are at an angle, so to make the air go through the slats, it will need to change direction, something it does not want to do. Without proper sealing of the shroud to the radiator, it will be easier for the fan to draw air AROUND the radiator than through it, which makes it wasted air in terms of cooling. Also, this reinforces the importance of an intact shroud which comes close to the fan. If there is a substantial gap, the fan will draw air from around the sides and not through the radiator.

Air will want to go over the radiator as well, so having a proper seal between the top of the radiator support and the hood is critical to stop this.

How is your fan clutch? If it is faulty or failing, the fan itself will not be spinning as fast or when it should.

Other minor things to check are to make sure the radiator and condenser (if present) are clear of debris.

Just my opinion, but I would make sure you are getting enough air to the right places first, and then re-evaluate.

I would then move on to having the radiator checked for blockage (although if you are pulling it to put in new seals, that would seem to be a good time to have it checked.

As for the sender being faulty, I'm not sure I agree. While it may be reading incorrectly (i.e. not accurately), what I see as important is that there was a delta between the two thermostats that indicated a higher temp. The post above which references checking to see if one was a high flow makes a good point. If you replaced a high flow with a standard one, you will slow the flow of the coolant, which could cause a reduction in the overall cooling capacity of the system.

There's definitely room to improve the cooling system (Aluminim radiator, etc), but none of those dollars will have the most impact without having the basic items in place to ensure enough air is getting to the radiator.

Sorry to ramble.... and good luck!

 

Great post SLVRSHRK ,rad has been checked and pressure tested with all new seals around the shroud and the chin spoiler is in tack.I will go through it all and see if there possibly is any air going elsewhere than where it should.Do you think the location of the temp. sendind unit from the head to the intake would be a factor? Thanx for the reply. J.S.H.

 

I'm still confused about where the temp sender is, and what kind it is. Can you post a picture, or maybe a link to the kind of sender you are using? Are you using an air temp sensor, or a water temp sensor?

 

It,s a water temperature unit brass and screwed into the intake almost beside the thermostate housing.

 

Umm, NO. This old "theory" that the water has to flow slowly so it has time to cool is completely and utterly 100% wrong. You want more flow if you want it to cool more.

Think about it. Do you want the air flowing through the rad slower so it has more time to remove the heat from the fins? NO! Same applies to the coolant.

 

That makes sense to me.

 

The purpose of a thermostat is to set the engine's operating temperature, and to get the engine there as quickly as possible, and to keep it there.

A cold engine will experience more cylinder wear, so you want the engine to get up to operating temperature as soon as possible. That is why you should NEVER run a car without a thermostat.