Jump to content

Overheating problem on 95 Cutlass (UPDATE, need help with diagnosing)


Cueman

Recommended Posts

Everyone,

 

I just got done replacing the thermostat on my 3100 yesterday, PITA! The car had been overheating and I replaced the water pump,thermostat, and temp sensor(the one right by the thermo) last summer so I figured I try the thermo first this time.. I have tried to bleed all of the air out via the bleeder screws, and think I have sufficiently done that. The problem now is that I have NO HEAT. The car is also running on the hot side. How can I tell if the heatercore is bad? Would a bad/plugged heatercore cause the NO HEAT and overheating temps?

 

Or should I start back at the waterpump again?

 

You advice is appreciated>

 

Brian

Link to comment
Share on other sites

Sounds like you have a bad heatercore. You can go to most full service auto repair shops and have the coolant system "backflushed" to see if there is a backup in the heater core. Do not confuse this with a "coolant flush" because these are two opposite services.

Link to comment
Share on other sites

Well my parents have had a heater core that was said to be on it's "last leg" about 3 yrs. ago. They recieved this point via a local mechanic to have the system "backflushed" once a year. Every year at the begining of winter the heat doesn't blow out hot, so they go get the system backflushed for $60. Every year it has resulted in nice hot heat coming from the vents.

 

Give it a try.

 

Link to comment
Share on other sites

Grab onto the heater core lines......if one is hot, and the other isn't....its plugged. If both are cold, you've got an air bubble in there someplace.

 

You can backflush it yourself.....just unhook the heater core lines off on the engine side and hook it to a garden hose....let it run for 15-20 min. each way....should take care of it...if it was plugged.

Link to comment
Share on other sites

in case the probelm is just an air buuble,

 

or rather...

 

what I have decided works best... back fill the cooling system with a long neck funnel at the hose going to the heater core.

Link to comment
Share on other sites

it could make a car run hotter as it is a system leak preventing your system from building up pressure.

 

I think you should do a funnel trick to try to overcome any air bubbles caught behind the tstat, a typical problem these cars seem to have after a coolant system service.

Link to comment
Share on other sites

I find that it helps to drill a 1/32 or 1/64 size hole in the thermostat. The water can't pass through but the air can. Just makes bleeding easier.

I tried it, but I think it makes my car take too long to heat up. Now I want to plug it and compare... it still lets some water through?
Link to comment
Share on other sites

Well, here is an update. After spending all weekend trying to bleed the system, it just fills back up with air. There does not appear to be any external leaks. So what I am thinking is the headgasket is leaking air in somehow.

Can anyone tell me how I can properly diagnose this?

I don't believe the LIM has been replaced either and there is 160,000 miles on the 3100.

Could the LIM be causing the air to enter the cooling system?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...