another water pump related question

[JasonStern]

I searched, but couldn't find anything regarding this.

Recently, I started to drive my 99 Boxster to work. I got about a block outside of my house when the low coolant light started flashing. I immediately turned around and drove a block home. It was below freezing when this happened, so I feared a freeze plug popped as I had just purchased the car, and while I had checked the coolant reserves, I hadn't checked the mixture ratio.

I get home and notice some coolant leaking from the front passenger side of the Boxster. Still convinced something froze but not having time to look at it until the weekend, I started the car up and drove it into the garage to prevent more potential freezing damage.

This is where things got bad. My girl had a friend come over to look at it, and it wouldn't start. Last weekend, I attached a Durametric and had no codes. I checked the oil and there was no coolant mixed in. The coolant reservoir was filled, so I knew that the leak was definitely on the thermostat to block side. Jacking the car up and looking underneath, the coolant leak appeared to be coming from the water pump or thermostat.

I had it towed to the shop, and they say the bearings in the water pump went out. They also say the motor is shot, but haven't done a compression test, which they want $300 to do. I really don't want to spend $300 on a compression test since I can pull the plugs, screw in a tester, and turn the motor over myself in about half an hour. But then I also don't want to pay for another tow fee to get it out of a potentially scamming shop. So...

1. (Fingers crossed) Is there a coolant pressure sensor somewhere that will cause the motor to not start if there is no pressure? I know cars have a safety mechanism like this for no oil, so I'm really hoping there is something like this for coolant and I just need to have the water pump replaced.

2. If there is a compression issue, how could it start, get in the garage, and then not start? Can the head really overheat in 15-30 seconds with oil but not coolant?

3. Continuing down this path, how could coolant not get into the oil?

4. Is there some hope it is just the head gasket? If not, is there some hope I can just have one or two of the heads reconditioned or replaced? Everything I read on here has been "engine problem = replace the whole engine", but I'm not in a position financially to blow $8-10k on a $9k car... :(

Thank you!

[JFP in PA]

I searched, but couldn't find anything regarding this.

Recently, I started to drive my 99 Boxster to work. I got about a block outside of my house when the low coolant light started flashing. I immediately turned around and drove a block home. It was below freezing when this happened, so I feared a freeze plug popped as I had just purchased the car, and while I had checked the coolant reserves, I hadn't checked the mixture ratio.

I get home and notice some coolant leaking from the front passenger side of the Boxster. Still convinced something froze but not having time to look at it until the weekend, I started the car up and drove it into the garage to prevent more potential freezing damage.

This is where things got bad. My girl had a friend come over to look at it, and it wouldn't start. Last weekend, I attached a Durametric and had no codes. I checked the oil and there was no coolant mixed in. The coolant reservoir was filled, so I knew that the leak was definitely on the thermostat to block side. Jacking the car up and looking underneath, the coolant leak appeared to be coming from the water pump or thermostat.

I had it towed to the shop, and they say the bearings in the water pump went out. They also say the motor is shot, but haven't done a compression test, which they want $300 to do. I really don't want to spend $300 on a compression test since I can pull the plugs, screw in a tester, and turn the motor over myself in about half an hour. But then I also don't want to pay for another tow fee to get it out of a potentially scamming shop. So...

1. (Fingers crossed) Is there a coolant pressure sensor somewhere that will cause the motor to not start if there is no pressure? I know cars have a safety mechanism like this for no oil, so I'm really hoping there is something like this for coolant and I just need to have the water pump replaced.

2. If there is a compression issue, how could it start, get in the garage, and then not start? Can the head really overheat in 15-30 seconds with oil but not coolant?

3. Continuing down this path, how could coolant not get into the oil?

4. Is there some hope it is just the head gasket? If not, is there some hope I can just have one or two of the heads reconditioned or replaced? Everything I read on here has been "engine problem = replace the whole engine", but I'm not in a position financially to blow $8-10k on a $9k car... :(

Thank you!

On what basis are they saying that the engine is "shot"? We get a couple 986's a month that come into the shop after the water pump quits, and there is rarely anything more to it unless the car was severely overheated, or shows signs of intermixing. There is no such thing as a coolant pressure sensor, the pressure is regulated by a valve in the coolant cap, and there is nothing in the car that will turn it off if the cooling system is open to the atmosphere.

I am also concerned about your comment that coolant was leaking at the passenger's side front of the car, which is a sign that one of the radiators or hoses has let go, possibly due to freezing if the coolant protection level is not correct. That may not be a good sign as freeze ups can cause localized overheating, which these engines do not like, but which is not always fatal either.

I am not over impressed by your shop's approach. While a compression test is a good idea, I would also be pressure testing the cooling system (takes about 15 min. or so) to determine what and where the leakage is, as well as testing the coolant to see if a freeze up was even possible. If your shop cannot map out a more reasonable diagnostic pathway, and continues their scare tactics, I think it may be time to take it to someone that has some idea what they are doing...............

Edited December 29, 2011 by JFP in PA

[JasonStern]

On what basis are they saying that the engine is "shot"?

Paraphrasing, but: "water pump went out. car won't start. must have no compression due to overheating."

We get a couple 986's a month that come into the shop after the water pump quits, and there is rarely anything more to it unless the car was severely overheated, or shows signs of intermixing.

I didn't notice any mixing when I checked the oil. I will call the shop to confirm before proceding, though.

I'd be disappointed if the motor overheated as, again, I went at most two blocks in low 30s/high 20s with motor speeds below 3k, but then I'm not too familiar with the Boxster motors. Maybe if the water pump was going out, low coolant was flowing and it overheated the night before? Or maybe even a while back causing small leaks/overheats? But then, shouldn't the temperature gauge had indicated such?

I am also concerned about your comment that coolant was leaking at the passenger's side front of the car

My apologies. I meant the front of the block on the passenger side - not the front of the car.

There is no such thing as a coolant pressure sensor, the pressure is regulated by a valve in the coolant cap, and there is nothing in the car that will turn it off if the cooling system is open to the atmosphere.

Darn. So there likely is some catastrophic engine failure? Otherwise, the motor should be starting regardless of the bad water pump. You'd think that would trip at least one code or give a more visible/audible notice of impending failure. :(

Presuming an overheat, how financially devastated am I? Is there a chance that resurfacing the heads and replacing the headgaskets can get the car running again? Or is an overheat on this motor likely to crack the heads, in which case can just the heads be replaced to get it running? Or am I really out the entire block?

Thank you for the quick, thought out response.

[JFP in PA]

Without a proper check out, I do not buy "catastrophic failure" has occurred. No intermixing has happened, so the water jacket must be intact. As far as "the car must not have compression", prove it. I'd bet it still does, and in spades. If it had no compression, it would spin over very quickly and sound funny while it was doing it, which you have not mentioned. Have them dump and save the oil and filter, if they look good, I’d still bet the engine is intact. Big time failures leave evidence.

Have them test the coolant for freeze point, take about 1 min. and most shops do it for free. If it isn't at least -10F, you may have momentarily overheated the car due to poor coolant condition allowing a freeze. Have them put the car up in the air and show you where the coolant is leaking from; unless there is physical damage (cracking or a hole), it can still be a freeze up. You may just have a blown hose or water pump, and nothing else. The hard start may or may not even be related to the overheat.

Edited December 30, 2011 by JFP in PA