The 89 MattMobile Build Thread.

[TallDarkandDisfigured]

If the hoses are hot, that means the pump is working. So that's a good sign. Considering the low cost of a thermostat you might as well replace it anyway since you've replaced the rad. If it doesn't solve the issue (which I think it should) at least it's a little peace of mind..

They only other thing I can think of is the fan... is the fan running when it gets hot?

 

[ralphee]

Replace the Thermostat, first port of call for sure. Could be fan, check its kicking in.
Also, could be an airlock, bleed the system through, squeezing all the hoses as you go.
Amazing project.......really great to see it all unfolding.

lee

 

[ralphee]

Hmm, apparently there is a temp sender on the waterpump too?

lee

 

[epilepticsquirl]

Like what the others have said, next step would be to check your ect sensor. By chance do you have on obd scanner? Yours is a 95 so I'm not sure whether you have an obd ii or obd I. Either way, they can be helpful little suckers. For example, you can plug in and see what temp your thermostat is putting out and compare that with an ir temp sensor.

Either way I'm damn envious of you right now. I just love car projects and all the hands on experience you'll be getting. *sigh* I'll just have to live vicariously through you yet again.

 

[the_batdemon]

Agree with all above, thermostat and radiator cap, if a new one didn't come with the new radiator. Check the sender on the temp gauge, as it's possible the coolant system is fine, but the gauge is getting a false reading.
Is the fan electric or mechanical? An electric fan's sensor could go bad too. I had this happen on a Mustang once.

 

[nullset]

Definitely check if there's air in the system. You should always bleed it after installing a new radiator.

 

[MattMunson]

Also, I'm pretty sure it's not the temperature sensor. After driving around for about five minutes, the coolant was boiling over and hissing out of the cap on the reservoir.

Next up is thermostat. I'll see if I can get that taken care of today.

 

[nullset]

Are the fans belt driven or electrical? Start the car and let it idle. Do the fans ever come on?

If they're electrical, try turning on the A/C (if so equpped). Do the fans come on then?

If the fans are electrical, you can always force them to run all the time by tying them to +12V. If that cures your overheat problem, then it most likely is a thermostat or temperature sensor somewhere.

If none of that makes the fans come on, then the fans are bad.

--buddy

 

[nullset]

Also, check and/or replace all of your fuses. This can help TONS when chasing electrical gremlins. At least remove them one at a time and inspect them. If there's any corrosion, replace them.

 

[MattMunson]

A few pics and words on replacing the radiator. Overall, a very fun little project, despite the fact that it didn't fix my problem.

The Project Workbench: Caprice Radiator Replaced

 

[Zombie Killer]

When the car runs hot, does the heater blow super hot air?


Also did you bleed the coolant system?

 

[MattMunson]

When the car runs hot, does the heater blow super hot air?

Dunno. will have to check that. one of the knobs for the AC/Heat control is busted off, so I'm not sure if I can even check it. :lol

 

[Zombie Killer]

I ask because if it does there is a good chance the waterpump is turning. If the thermostat is easy to get at i would just yank out the thermo and leave it out for now. If it is hard to get to replace it while you are there. If that does not take cre of it then your waterpump impellor could be off the pump. If your waterpump has a hose connection close to the impellor you may be able to disconnect the hose and belt and just stick your finger down the hole and see if you can feel the impellor spinning while turning the pulley by hand. If your fiinger is not long enough try a screwdriver. Just to make sure, you don't have a coffee looking substance on the oil filler cap do you?

 

[TallDarkandDisfigured]

Gonna have to stop all this mechanical talk, you're scaring the geeks away.. :lol

Looks like you did a bang up job on the Rad swap. Not many parts left that could be causing the issue now. I'm still putting my money on the thermostat.

 

[TallDarkandDisfigured]

Just to make sure, you don't have a coffee looking substance on the oil filler cap do you?

I think he said he already checked that one out and ruled out the head gasket..

 

[MattMunson]

I think he said he already checked that one out and ruled out the head gasket..

Correct. Oil cap is totally clean.

Thermostat is very easy to access, which is one of the reasons I'm going to tackle that next. It's also only an 8 dollar part, which is cool. Though I think I may have to buy a torque wrench. AutoZone has a loaner, but it's a tool I think I will get a lot of use out of once I'm building the mechanicals back up.

I appreciate all of the great suggestions in this thread though. Despite my frustration at still having the overheat problem, this is actually a lot of fun.

 

[TallDarkandDisfigured]

A torque wrench is the mechanical equivilent to the dremel. A must have.. It'll pay for itself in peace of mind when it comes time to put the rims on if nothing else..

 

[MattMunson]

I can't find anything in the haynes manual about bleeding the cooling system. Anyone have any ideas?

 

[MattMunson]

Think I found it. Looks like there is a bleeder valve on the thermostat.

 

[Zombie Killer]

Thats it.