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fltstone
11-09-2012, 11:22 AM
On her way home from college this week my daughters 97 b5 ran hot on her. As I had always told her if you ever think your running hot pull over and call me. So I had AAA bring the car home and to my surprise the driver said that he started it up and drove it onto the flatbed. So far all I can find is coolant is just below the MIN on the coolant reservoir. It starts up and runs fine with no sign of leaks. The only sign of any leak is on the engine block next to the oil cooler. My question is how do I determine where I'm losing coolant?

skim464
11-09-2012, 11:32 AM
Well if it overheated, I would like to advise you to run a compression test to check any internal damage as well as blow by gas test.

The only way to determine where coolant is leaking is to chase the leak. common spots on that car is the rear flange according to what I've seen

AudiNFS
11-09-2012, 11:35 AM
What's "ran hot"? Like needle got over half hot or needle got to "H" hot?

fltstone
11-09-2012, 11:54 AM
Her description was that the Temp. Gauge went all the way over to the H and that the check engine light came on. I just started the car up and let it run and the Temp. gauge is running toward the H.
A compression test? Ok on my way to Oreilly's to get a tester now.

walky_talky20
11-09-2012, 12:44 PM
Could be water pump failure, that's pretty common. Hopefully she got it shut down quick enough before it killed anything. Checking the water pump is pretty easy, you just drain the coolant and remove the thermostat to check the impeller.

Seerlah
11-09-2012, 01:39 PM
If the gauge was pegged, I would not be surprised if the coolant boiled out the overflow on the tank. That coolant will need to come out anyways since you will need to fix the issue that is causing the overheating. A full TB job would be optimal at this time, because it is more than likely stuck closed t-stat (doubtful) or your water pump needs to be replaced, as walky_talky20 stated. Take this opportunity to do a full TB job.

For checking where the leak is, look for dry or caked up white/pink residue. You should be able to spot it. The common spots in the engine bay is the t-stat housing under the intake manifold (right by the alternator), rear coolant flange on the back of the cylinder head (where one coolant temp sensor is located), and the water pump. You can also turn the engine over and see if you can spot where the coolant is leaking (coolant has to circulate first). But I think it came out the overflow on the reservoir, so see if it is clean underneath the expansion tank and area below.

Good luck!

csosnowski
11-09-2012, 04:33 PM
The 97's should be able do the water pump without replacing the tb. I vote thermostat stuck closed.

as another member suggested; compression test, cooling system combustion gas test. these are to see if there was any damage to the head gasket. you could also do a cooling system pressure test and possibly pinpoint the leak that way.

if you have coolant residue near the oil cooler then the odds are that the rear coolant flange is leaking. Look around for crusted coolant to track down the leak, as was mentioned earlier.

seanj130
11-09-2012, 05:12 PM
Waterpump... And you lost coolant when it overflowed due to high pressure through the cap. Also pick up a new cap. When my system overheated and I lost pressure through the cap, The cap was bad. They are 6$ at autozone.

fltstone
11-10-2012, 04:37 PM
I got the compression test done today. Cylinders 1-4 are 70, 40, 85, and 110. Coolant flange had no leaks so I ruled it out. I degreased the engine than started the car and let it run until the heat gauge reached 1 o'clock. still no leaks. My guess is that the fluid lost was threw the over flow on the reserve tank. With the heat on high all I got was cold air, so I think it's the thermostat or the water pump. So either way it's time to get a timing belt kit. Who has the most reliable kit?

geeky
11-10-2012, 05:08 PM
you do realize 40psi of compression is NOT a good number. Try a leak down test and if you're findings are similar that head is toast.

Seerlah
11-11-2012, 02:14 AM
The car would run very very sluggish at those numbers, if it ran at all (hiccups if running). I am thinking he did the test wrong.