89 overheating
Thread Starter
Le Mans Master
Joined: Mar 2003
Posts: 6,477
Likes: 1
From: Albuquerque NM
St. Jude Donor '08-'09-'10-'11
89 overheating
I've been having some problems with my car overheating. My coolant levels are fine. It heats up to 245-250 fairly easily, and will go higher unless shut off.
Will pulling the radiator out and cleaning it out take care of this, or is it possible that other problems are present?
Thanks.
Will pulling the radiator out and cleaning it out take care of this, or is it possible that other problems are present?
Thanks.
Race Director
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Originally Posted by Fartleker
I've been having some problems with my car overheating. My coolant levels are fine. It heats up to 245-250 fairly easily, and will go higher unless shut off.
Will pulling the radiator out and cleaning it out take care of this, or is it possible that other problems are present?
Thanks.
Will pulling the radiator out and cleaning it out take care of this, or is it possible that other problems are present?
Thanks.
Pulling the radiator and cleaning should go a long way to improving this situation. I do mine once a year, it's amazing how much stuff gets in there!But here are some other considerations
Are your fans coming on? At what Temp?
The temps you are mentioning are really way too high, is it possible the temp sensor is bad? They do go south!
What are your oil temps when engine temp is 250?
When you start up, while it is still relatively cool, can you or have you removed the radiator cap to see if you are getting coolant flow through the Rad? Coolant should be flowing toward the pasenger side of the Rad, at least on the L 98
Last question, how long has the coolant been in there and how old are your hoses?
seeya
Jack
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Pull the radiator schroud, look for debris-it's amazing how much junk, leaves, plastic bags etc. get sucked in. common problem at least on our C4s. And you might want a lower temp fan switch too. 
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
89's are notorious for blowing head gasket between #5 and #7.
This would heat up the engine. Pull the #5 and #7 spark plugs and crank the motor. See if any coolant sprays out or is otherwise present in the cylinder.
You may just check all the cylinders. Maybe do a pressure check one cyl at a time(by adding compressed air into the plug hole) and see if there is any "gurgling" by the rad cap.
Is the rad cap holding pressure?
Are the fans kicking on?
What temp switch do you have installed?
What thermostat is in there? Is it stuck?
Removing the rad is pretty easy, reverse flush it. Maybe pour in some of that cooling system cleaner before service.
Let us know how it turns out.
This would heat up the engine. Pull the #5 and #7 spark plugs and crank the motor. See if any coolant sprays out or is otherwise present in the cylinder.
You may just check all the cylinders. Maybe do a pressure check one cyl at a time(by adding compressed air into the plug hole) and see if there is any "gurgling" by the rad cap.
Is the rad cap holding pressure?
Are the fans kicking on?
What temp switch do you have installed?
What thermostat is in there? Is it stuck?
Removing the rad is pretty easy, reverse flush it. Maybe pour in some of that cooling system cleaner before service.
Let us know how it turns out.
Last edited by pablocruise; Nov 29, 2004 at 08:16 PM.
Advanced
Joined: Nov 2004
Posts: 64
Likes: 0
From: Houston TX
your thermostate is probly stuck open from it running too hot. Try making sure your a/c fan is running. It's a good possibility the radiator is cloged. This is very common also if it is a stock radiator the seems on the side are badly cracking. If so, replace it ! This happened to me 6 mos back. I can now leave the car at idle in 95 degree weather for quite awhile.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Since it's an '89, and particularly if the mileage is somewhere between 40 and 60k, I agree that you should check #7 for signs of a leaking head gasket (most have been repaired after that mileage). Compression may be normal, but overheating isn't a good sign. If it's been leaking for some time, galvanic corrosion builds up in the head cooling passages and plugs the radiator and the heater core.
Look for rust on the spark plug threads or an electrode that looks different from all the others. If if the coolant is brown or rusty looking, that's another indication. I'd take the radiator to a shop and have it boiled out or simply replace it and flush the block with a cleaner. To get everything out of the block, remove the oil cooler hose at the oil filter on the driver side and the knock sensor on the passenger side.
Look for rust on the spark plug threads or an electrode that looks different from all the others. If if the coolant is brown or rusty looking, that's another indication. I'd take the radiator to a shop and have it boiled out or simply replace it and flush the block with a cleaner. To get everything out of the block, remove the oil cooler hose at the oil filter on the driver side and the knock sensor on the passenger side.
Instructor
Joined: Apr 1999
Posts: 219
Likes: 0
From: no. little rock arkansas
my 89 convertible was afflicted with cooling problems.
first pulled the radiator and cleaned all the debris between the
radiator and ac condenser. lowered from 220° cruzing 70mph to
205°. next replaced the ac condenser went to 195°. changed
the tstat to a 180° and now 184° at 70mph and 200° through
town (stop and go). with ac on 220-205° stop and go.
airdeano
first pulled the radiator and cleaned all the debris between the
radiator and ac condenser. lowered from 220° cruzing 70mph to
205°. next replaced the ac condenser went to 195°. changed
the tstat to a 180° and now 184° at 70mph and 200° through
town (stop and go). with ac on 220-205° stop and go.
airdeano
Burning Brakes
Joined: Oct 2002
Posts: 1,060
Likes: 0
From: Dixon Ca
Are you going by the gauge on the dash cluster or by using one of those digital hand held laser temp readout. The reason I ask is because I found out 2day (11/29) that my dash cluster gauge is off by 25 deg. The laser temp readout was 195 at the thermostat & other areas. My gauge read 220 deg. 
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