1997 STS serpentine belt popping off

[Duce]

Hello, I'm new but I have a 1997 Cadillac STS, recently I've had some issues with this car. But my issue now is that I think I have a blown head gasket. My serpentine belt has popped off several different times. Once when I was adding coolant to the car while I had it running. It gurgled the coolant out and all over my engine and caused the belt to pop off. Then a few days later it over heated on me and popped the belt off again. I need someone who knows about Cadillacs to tell me something besides a new head gasket which will cost me two arms and a leg. I've read several different articles but nothing to what I'm actually experiencing. LOOKING FOR SOME INSIGHT PLEASE. I'm not willing to give up on her yet. Thanks Duce

[KHE]

Do a block test to see if there are exhaust gasses in the coolant - there is a TON of information in the archives on this. THe overheating should not cause the serp. belt to pop off - you micht want to check the bearings on the alternator, power steering pump, etc.

[Duce]

Yes exhaust test sounds good to try, but of course I'm not mechanically inclined. Could you explain an exhaust test to me.

[winterset]

The waterpump in not on the serp belt. Its on its own belt on the other side of the engine. This sounds more like your belt tensioner. But you need to inspect each pulley in the system for play. The leap from a belt slipping free to a Headgasket failure is a bit much for me.

[Duce]

but why is my car over heating and the belt popping off. I was told it could be because of a possible blown head gasket

[rockfangd]

The coolant blowing out of the surge tank is blowing onto the belt which is causing it to blow off. Check your radiator cap and make sure your coolant mixture is correct.

[Cadillac Jim]

There are a lot of reasons a car can overheat. Pulled head bolts is the 800-pound gorilla of overheating problems and isn't the cause in most of them. The most common cause I've seen here is a clogged bypass hose. It's the hose from the thermostat housing that hooks onto the "bolt with a hole" and goes to a metal hose which passes under the cover over the fuel injection, then has another rubber hose about 8 inches long that hooks to the overflow tank. If you unhook it from the overflow tank and start the engine, it should flow freely. If not, it's clogged.

Other reasons include, but are not limited to:

• Less than 50-50 Antifreeze in the coolant, particularly in hot weather.
• A radiator cap that doesn't seal, or the wrong radiator cap for your car.
• Problems with the fans.
• Leaves or debris in the A/C condenser or the radiator.
• Missing or damaged air shields below the radiator. That's the tar paper stuff that guides air through the radiator.
• Sticking, wrong, or miss-installed thermostat.
• A leak in the system. The radiator hoses, the heater hoses, and the radiator tanks are places to look. Also the heater hoses, heater core, and the hoses on the surge tank can leak. Look for a cracked surge tank.
• A problem in the heat exchanger for the oil cooler (right tank) or transmission cooler (left tank) in the radiator tanks.

EDIT: I forgot to add the water pump, which is on the transmission side of the engine, front bank, and driven by a camshaft:

• Bad or leaking water pump.
• Bad or slipping water pump belt.
• Bad water pump belt tensioner arm or pulley.

[Duce]

Thanks this all sounds way better than a head gasket. I can't seem to find a Cadillac mechanic around here. I have something to go by at least. You know they see a woman and see dollars signs. I would never let them tear here down like that without at least having some options. Thanks again.

[Cadillac Jim]

Ah, a woman talking to [some] mechanics. We are just beginning to show awareness of the next layer in the onion in gender equality, I'm afraid.

But, not all mechanics are impaired when it comes to talking turkey to everyone. Getting informed, as we will help you do here, will help a lot.

You don't need to find "a Cadillac mechanic" for your car. When it was new, there were few cars like it, but the innovations of the Northstar system have been so widely imitated that most qualified mechanics can solve your problems with the serpentine belt an overheating. To begin with, watch for the ASE certification symbol on a certificate on the wall:

Look at the date; it should be less than five years old. Look at the name, and see if the technician named is present on the premises and if he is working on your car, or supervising who will be working on your car.

The serpentine belt problem is separate from the overheating problem. Both are pressing so you can't just solve one and then the other, apparently. But serpentine belt problems are usually pretty simple to solve. You take off the serpentine belt and make sure *that* is OK, then check the engine damper wheel for being on tight and not wobbling, then check all the pulleys for turning freely and not wobbling, then, most likely, determine that you have a bad tensioner arm or pulley. Given that, you can focus on the overheating problem. I would start with checking the bypass hose. You can do that yourself.

[Duce]

Yes, my father was a mechanic grew up in the shop, but find that I still get a little intimidated when I take my car to a shop. I will make sure I check the certificates. I will check the by pass hose and see what happens. I've been reading some other threads and find that's where they say to start.

[Cadillac Jim]

Develop a game face to use when going to the shop. I would also get familiar with running the OBD codes for your car and know what code are present, and which of those are CURRENT and which are HISTORY, when you take your car in. Check the codes again when you pick up the car.

You can check the codes in a few seconds on a 1997 STS. With the key on, using the A/C buttons, press <Off> and the up rocker on Pass Temp (<Pass Warmer>) together for a few seconds until all the dash lights come on like you just turned on the key, then release both. The car's computers will then give you the car's codes on the driver's information center. A typical code will be

PCM P0420 CURRENT

where the first three letters tell you the module that threw the code, P0420 is the code, and CURRENT or HISTORY tell you whether the problem is being detected right this second or not.

Overheating problems usually don't throw codes, so this will provide a snapshot of what is going on with the engine but probably not help much with the overheating problem. But, whenever you see a warning light, you know that the reason that the warning light was turned on is that there is an important OBD code that is CURRENT.

[Duce]

Oh ok for some reason I recall that from my other 1997 I had. But I will try that to check the codes before and after.

[Duce]

Ok, found out the bypass hose is split. All the pulleys seem to be fine, going to change the hose put the belt back on start her up so can check the tension pulley out. Ran the codes and came up with these. PCM P0141, P0147, P0155, P1153 and RSS C1738, I'm going to look these up and see what I find out.

[Duce]

Ugh ok I looked them up the Powertrain Control Module codes all have to pretty much do with my O2 sensors which I've had all three of them replaced and a new catalytic converter put on. The RSS code is for my air shocks which I had the pump disconnected and now I directly put air in them when needed. I didn't want to hear about the O2 sensors again. But first get this over heating problem taken care of and then back to the O2 Sensors. Any in put on why then would be a problem again.

[Texas Jim]

P0141 O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 2

P0147 O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 3

P0155 O2 Sensor Heater Circuit Malfunction Bank2, Sensor1

P1153 O2 Sensor Insufficient Switching Bank 2 Sensor 1

C1738 Air Suspension RR corner Down timeout

or possibly

C1738 Exhaust Solenoid Valve Short to ground.

[Texas Jim]

Ugh ok I looked them up the Powertrain Control Module codes all have to pretty much do with my O2 sensors which I've had all three of them replaced and a new catalytic converter put on. The RSS code is for my air shocks which I had the pump disconnected and now I directly put air in them when needed. I didn't want to hear about the O2 sensors again. But first get this over heating problem taken care of and then back to the O2 Sensors. Any in put on why then would be a problem again.

Just my opinion... but with all three of them acting up again, I would be looking at the wiring and not the sensors.

[Duce]

Thanks. Will check on that after finish up with the over heating issue. Found the belt on the water pump was snapped, pump seized up, both pulleys are toast, so replacing the pump, belt, the one pulley now, the crank shaft pulley has to be ordered, going to do that through the GM dealership in the morning. and no of course I'm not doing the work myself but I am overseeing everything that needs to be done, and helping yes I will hand you that wrench. I appreciate all the advise that has been given and where to start. I will let you know how everything turns out after these parts are put on.

[rockfangd]

you mean the cam pulley?

And you can replace the WP tensioner rather than just the pulley.

Good progress so far.

[Cadillac Jim]

You should verify which parts are bad before you order them. The crankshaft damper pulley and the cam pulley for the water pump very rarely go bad and they are very expensive to replace.

[Duce]

you mean the cam pulley?

And you can replace the WP tensioner rather than just the pulley.

Good progress so far.

yes thank you your right

[Duce]

You should verify which parts are bad before you order them. The crankshaft damper pulley and the cam pulley for the water pump very rarely go bad and they are very expensive to replace.

Yes thank you, the tension pulley was pretty rough looking.

I'm looking for this now.

this was pretty beat up on the inside. Put the pump in with new seals. Added some fluid and is leaking from this housing. I've called all the auto part stores in town and called the GM dealership, which they say was discontinued. Hate to go pull from a salvage yard. But this is what its looking like is going to have to happen. I also checked Rock Auto parts and no luck. Any suggestion where else to try.

[barczy01]

I have one I can sell you. Its called a water pump housing.

[Cadillac Jim]

This is the crossover housing. I've never heard of anyone having to get a new one before.

[Duce]

This is the crossover housing. I've never heard of anyone having to get a new one before.

the inside of it is chewed up. As soon as it gets completely off I will snap shot it so you can see.

[rockfangd]

I would like to see this also. Wonder why the housing would be chewed up inside. I could see maybe some corrosion in the housing by the cover, Another thing is if not removed properly the water pump can damage the housing. But I have yet to see one mself