Leak down test results

[Boost92awd]

First off, 1992 plymouth laser, 69,000 original miles. Mods are UICP, BOV, Free Mods, stock boost.

Well the cars been sitting for 2 monthes now, was parked because it started running hot but it wouldnt over heat.

So I did a leak down test last night and heres the results.

Not sure if its percent, but I was told anything over 30 is bad.
Cylinder one - 60
Cylinder two - 50
Cylinder three - 26
Cylinder four - 23

Also While I was doing this, listened for air leaks at the intake and there was nothing. Then listened at the exhaust and there was nothing. Listen through the dipstick and you could hear air leaking into the crank case. I was told it could be possible bad piston rings, but I need a second opinion. Also we were watching the coolant level the whole time. When I first started the test it was full to the top. By the end up the leakdown test it had gone down alittle bit, but there was no bubbles or anything. Any help would be greatly appreciated. Also before it was parked I noticed for the last couple monthes that I would have to fill the coolant about once a month cause the low coolant light would come on. The car runs and drives right now but I havent had it running long enough to find out if it would over heat. I also noticed its been leaking coolant from the timing belt side of the motor, not sure if it related to this problem or its just another problem.

 

[99gst_racer]

If the coolant temp is higher than normal, and it's slowly consuming coolant, then it's probably the head gasket.

 

[Boost92awd]

Yes its doing exactly what your saying, its running hotter and it has been going through coolant since I bought the car, Had to usally fill it up about once a month.

I will post a log up on sunday when I get back home from up north, on the coolant temp. I have noticed it is leaking coolant from the timing belt side of the motor. But there is no coolant in the oil.

 

[Boost92awd]

If the coolant temp is higher than normal, and it's slowly consuming coolant, then it's probably the head gasket.

What would explain the air I hear leaking into the crankcase when doing the leak down test? Wouldnt it be bad piston rings? Its starting to sound like I have multiple problems.


I will be doing a coolant pressure test and a log of coolant tempertures tonight. I'l post up the results when I'm done.

 

[99gst_racer]

What would explain the air I hear leaking into the crankcase when doing the leak down test? Wouldnt it be bad piston rings? Its starting to sound like I have multiple problems.

It's possible that you were leaking coolant into one of the cylinders. That could have washed the walls to the point where it would allow more air to escape past the rings during a leakdown test.

But you're right - It's possible to have more than one problem.

 

[92awddsm]

My guess is that leakdown was bad because of rings. Retest leakdown with oil in the cylinder just like you would on a compression test. As for coolant, sounds like it is leaking out of the water pump and not the hg. Pressure test the coolant system to determine where the coolant is going.

 

[Boost92awd]

Alright I just ran a log on the coolant temperture. I let it idle for about 15 minutes and the coolant temp was hoving around 219 degreez and the fans would not kick on. Drove it around the subdivision and it was stay right around 206-213 degreez. Drove it to the gas station cruising at 50 MPH, and the temp was staying right around 209. Got to the gas station was still around 209. Let it idle for about 1 minute before I turned it off and the temp went up to about 215 degreez. Turned car back on after filling up and the fans kicked on. Drove all the way back home no problem with temp. There was no smoke at the tail pipe. Its definitly running alittle hot but not as bad as it was the last time I drove it.

Also wasnt able to do a coolant pressure test, didnt give me the right peice so I'l try to get that done tomorrow.

 

[1gDSM4g63]

If the coolant temp is higher than normal, and it's slowly consuming coolant, then it's probably the head gasket.

I always hear that a blown head gasket will cause white smoke from a exhaust and coolant in oil but can it cause coolant leaking straight from the engine when the car is running and build coolant pressure?

 

[99gst_racer]

I alway hear that a blown head gasket will cause white smoke from a exhaust and coolant in oil but can it cause coolant leaking straight from the engine when the car is running and build coolant pressure?

Not all failed head gaskets will act the same. It all depends on where the gasket failed.

I'm in the process on doing a head gasket job on my Grand Prix right now. The gasket failure was a crack in the firing ring of the gasket. It was allowing compression gasses to enter the coolant tract. It was causing it to over-pressurize, and pushing coolant into the overflow. It was also constantly putting air in the system, so I had a fluctuating gauge and no heat. I had no oil in the coolant, or vice versa, and it didn't burn much coolant.

In many cases, you can determine how/where the head gasket failed just by examining the symptoms.