tenebrous

I have 1984 C4, whenever temp gets around 200-210, sounds like a relief valve or something opens every 3-5 seconds, looks like it blowing out steam, could this be a overheating issue?

antfarmer2

temps are good might need a new radiator cap get a good one!!!!!!!!

John A. Marker

You posted in both General and Tech....

Where do you see the steam or smoke? You need to be specific and identify which area.

tenebrous

ok i'll try this

tenebrous

What type would you recommend?

don hall

[QUOTE=tenebrous;1590989749]What type would you recommend?[/QUOTE]

I'm assuming you are asking what cap to buy (?).
Most caps are made by 'Stant', and packaged under many
brand names. According to Stant people, all newer caps are designed for both open and closed systems. I think all Stant caps have the letter 'S' stamped in the brass rivet in the cap.

Just buy a cap from AutoZone, etc., and you will be fine.

If a cap gasket is damaged, air will enter the cooling system. This negates the pressure build-up which is needed to raise the boiling point.

If the system is boiling, you may see steam coming from the cap, if the gasket is damaged. If there is smoke, that is another concern.

Check the cap gasket for damage. Replace, if necessary. Then check the coolant level in both the radiator and overflow bottle, fill, if necessary.

tenebrous

Thanks bro, i'll try this, hopefully this is the problem.

don hall

Also, any breach in the cooling system will negate pressure build-up. So check for loose hose clamps, frayed hose ends, any condition that may allow air into the cooling system.

John A. Marker

He also posted in General. Where he has answered my question...WHERE...."near the air filter" on the 84 that is no where near the radiator cap. One response in the other post was to check the T-stat housing. I suggested that he warm up the car until he hears the noise, remove the air cleaner and then check hoses, T-stat housing area for the steam he is seeing or sign of a leak.

tenebrous

ok, put new radiator cap on, still having same problem. checked hoses and clamps, all are good. when I shut off the car, I get a hissing sound, like the heater is still blowing

antfarmer2

the cap was the first thing I thought to cheak. but many other things can leak. get a pressure tester that some places will loan you and find your leak.

don hall

You didn't mention if you checked the coolant level (?).

With a cold cooling system, remove the rad cap. Run the vette until the t-stat opens, and look to see if the coolant is circulating. If no circulation, t-stat may have failed closed, clogged with rust, or pump could be faulty.

Still have steam or smoke? Source?

tenebrous

I could have a bad fan, it's not kicking on at all, do know that much about cars(just a reminder)

don hall

Yes, I know enough that the fans should activate at a predetermined temp. Don't know the fan temp activation for a 1984, but a member, or google will inform you. 210 is not sufficient to activate the fans.

Coolant full, and circulating?

tenebrous

yes coolant full, will check to see if it circulating tomorrow, I also just put a relay switch in, are there any other fuses for fan?

tenebrous

could it be a bad cooling fan switch?

ccrazor

From the 84 FSM the switch for the fan is rated to operate at 238* .. To check the switch, disconnect the switch (between #6 & 8 plugs ) and with ignition set to run, ground the connector, the fan should run..

don hall

If your max temp is 210, the fan is not your problem.

It is possible the temp gage is faulty, and the temp is not accurate.

If your head gasket has ruptured, the temp would rise very rapidly, greatly exceeding 210 temp, and you would see a coolant loss.

tenebrous

ok, the highest the temp has got is about 214 while driving, then drops to about 184. when I crank the car and let it warm up the symptons start once temp reaches 200-210(about 5-10 mins)steam comes from area under where air filter and fuel injectors are, just below the middle pulley. have it on video,but having trouble uploading it.

Cruisinfanatic

as I said, put the video on utube and then post the link here