New timing belt = overheating?

[mattic]

I just had all new belts installed in my '91 cab and all of the sudden the car is overheating. I bought it three weeks ago, 300 miles away. Drove it home with no problems and had been driving it without issue. In fact, the temp gauge hadn't even gone above the first tick mark. Late last week I had a local garage change the timing belt and all the other belts and rollers using the Conti kit from Pelican. I picked it up yesterday. Driving less than three miles from the shop to work I noticed a very prominent belt whine, but it didn't get hot. At least the lights didn't come on. During a short drive to get coffee yesterday afternoon (less than a mile each way) the temp and ! lights came on as I pulled into the lot. Hoping to get home last night they came on about five miles up the highway, and two miles from home. I added some distilled water, about 1/2 gallon, to see if I'd be able to get it back to the shop this morning and by the time I got to the first gas station on the way, about a mile from home, the lights were back on. By the time I got it back home the coolant was boiling and I ended up with a large puddle on the garage floor. What could they have done to cause this? I'm sure I'm in for a huge battle with the garage, so the more wisdom I can collect before that begins the better.

I had it towed back to them this morning.

[manydubs]

So, they had everything apart and did not bother to replace the water pump?

Did they change out your coolant?

Maybe a air pocket issue? Bad water pump due to tension of new belt?

[mattic]

I should also add that the car has only 40k miles on it, and as such I did not have the water pump replaced. I had them do the belts because I was told the belts were changed at 30k, but they could not remember when that was and had no paperwork on it. Upon inspection of the old belts they looked about brand new.

I added this before seeing the first reply. My guess is they messed the water pump up by overtightening the new belt, but I don't know how viable that is.

[looneybin]

if they took off the upper hose to do the belts, they probably didn't bleed the system & you are having an air embolism in the coolant system.

BTW - i replace my belts last May & just last weekend had to replace my water pump due to the new belt tension eating the old pump bearing.
It was a terrible grinding noise

[ewalt98]

I would have them check for air pockets first. The 944 cooling system must be vented to remove any air pockets when hoses are disconnected or replaced.
Also, make sure the power supply to the fans are hooked up and functional.

[smokin_944]

+1 I would say check the belt tension. Immediately. Is the local garage knowledgeable of 944 cars? The reason I ask is because some garages do not have a clue when it comes to belts and WPs and they are crucial to the proper running of the 944 series cars. Find a Porsche shop, or one of the local 944 wrenchers near your place to check over the set-up. The car shouldn't leak a drop unless they screwed something up bigtime!

[smokin_944]

Looneybin, were you using a 9201 belt tensionning device for your new belt?

[looneybin]

Originally Posted by smokin_944

Looneybin, were you using a 9201 belt tensionning device for your new belt?

the local indie Porsche shop did the tension on the belt change last may.
I did it by hand last weekend

[mattic]

Thanks for the initial replies. The shop is European Auto Specialists in Sharronville, Ohio, and I found them from the local PCA web site. They've been here for more than 20 years with the same head mechanic. I asked a few key questions before deciding to take it there and the head mechanic had the right answers. The problem may be though that the head mechanic didn't do the work.

When I speak with them later today here are the questions I've gathered from this thread and a couple others. Please let me know if there are other questions I should ask:

Did you remove the top coolant line to change the belt, and if so, did you vent and refill the system properly?

What tool did you use to set the tension on the belts?

What spacing was used for the roller? (I think it's supposed to be 0 - .02 mm)

[mattic]

Also, in response to the cooling fan question above. No, I know the fans aren't operating correctly, but they weren't operating correctly before I took it there when I had no cooling issues. I did run a jumper at the relay connection to make sure at least the second fan was running last night and that made no difference. I plan on doing the full diagnostic from Clark's Garage when I get the car back. I'm guessing I have a bad relay, but need to check the passenger side fan motor and switches, too. The driver's side fan runs when I jump the relay and have the key turned.

[smokin_944]

Mattic, you could have one of those freak of nature junctures where the correct fan operation launched (failed) at approximately the same time as the belt change occurred thereby making you believe the 2 are related. If one of your fans cough it up, or the coolant cap is bad for example, the car will spit coolant out without it being your waterpump failing. Did you identify the source of the coolant leak? I think taking a look at Clarks is a wise and prudent thing to do in this instance. Much of the troubleshooting can be done without putting the car at risk...

[indio76]

with a bubble in the circuit you should have experienced irregular or no heating coming from HVAC unit..did you notice that?

About temperature, mine too drives a little bit hot. I mean very often goes up to the second white line for a moment, but then fans kick in and goes ok. I experienced a ! light only the day I got the car...the previous owner did not inform me of non operating fans.

BUT in this condition I drove the car from London tu Turin (Italy)...is about 2000 miles... with no other problems.

Like you I changed the belts are rollers shortly after this trip and I noticed a good improvement in the temperature. Still I'm not happy (next step will be:radiator and 2 complete flush)

BTW take care of the head gasket .. after so many ! I would check it if I were you...

[mattic]

Yeah, well, it's worse. After getting home from the office today the coolant puddles have dried to leave large spots of engine oil.

As soon as I noticed the temp gauge rising I turned the heat on full blast and it was blowing hot air.

[indio76]

Worts to read Cooling System Troubleshooting.

Your coooling fans don't work?The switch in the radiator may be bad and stuck open, fuses missing or bad relay. Easy check.

Bigger problems if you find oil in water...

[89-944NA]

indio, how do you read "worts"?

[Slam]

"After getting home from the office today the coolant puddles have dried to leave large spots of engine oil."

This plus your story about boiling coolant and overflowing leads me to suspect the head gasket now - it seems you may have overheated badly enough to warp the head. I sure hope not...

[nynor]

head gasket.

[Rasta Monsta]

I wonder if somebody at the shop fired/drove it before filling the cooling system?

[indio76]

Originally Posted by 89-944NA

indio, how do you read "worts"?

worth...sorry, late hour and bad english...

[indio76]

Originally Posted by Rasta Monsta

I wonder if somebody at the shop fired/drove it before filling the cooling system?

Good question...hard to demonstrate, let's say impossible.

I would replace head gasket anyway, after so many overheating and flush, flush and flush again the whole system.

Not from the same workshop...