348 Overheating

I searched archives, but didn't find much. Problem is, at idle temperature starts creeping up close to 250, after pulling away temp comes down to normal. Both fans are operating. It did spit up some coolant today after I shut it off. It seems to be associated with RPM, higher it is, cooler it runs.

The car has 6,800 miles on it so I can't beleive it's the water pump. Someone tell me it's a thermostat, or cap Please

Any ideas? Thanks.

 

Are you saying that you've already bled the cooling system at the appropriate places and yet you still have the problem?

 

Well that was done about 1,000 miles ago when the service was done. Hadn't thought about it needing it again.

 

Try bleeding the system. Also when was the coolant last changed?

 

Well, if that 1,000 miles was three years ago...would you please drive that thing more!

Bleeding (or maybe better called "checking fullness" in your case) has got to be the place to start. Your OM should have a fairly decent illustration showing the various bleed port locations.

 

Location of cooling system bleeder valves:

 

Isn't there a 3rd one on the thermostat housing too?

 

Coolant changed about 4 months ago.

I'm on it, thanks guys

 

OK I'm pretty sure there's air in there, but do I take the expansion tank cap off while bleeding. I had it on and steam was comming out of the screws no fluid, got too hot and I shut it off.

 

Oh brother talk about feeling like an ass. There wasn't any water in the darn tank. I guess this is just another example of trusting someone to do a service. You never know what they've really done.

Never ASSume anything.

The bleeding procedure makes allot more sense now!

Bless this board.

 

As long as you're making progress, inspect the tank cap carefully and make sure the rubber is still in good shape. If the car has been sitting for a long time, the rubber might be brittle and yucky.... also a possible point of failure.

 

Raymond -- There's another possibilty and that's that you have a small slow coolant leak somewhere that's not very noticeable but over time gets to be a problem (there are too d*mn many water hose connections on the mid-engine F). If things go well after refilling, you might still try rebleeding the system again in a month or so just to see if much air is reaccumulating in the system -- just a suggestion...

 

Looks like they added fluid once.

With any ride...

(disclaimer) relieve pressure before uncapping and adding.

After filling, run engine.
Top it off, run engine.
Top it off, run engine.
Top it off, run engine.

 

Well I think the problem is fixed, but I'll continue to monitor as per all of your suggestions.