HELP I Hope this is not a Huge Problem

[nick368]

I have been restoring an 87 GN, and the car has been coming along nicely. However, I went to drive it tonight and when I got on the car a little bit...not much really, the turbo kicked in and then I started hear a light tapping noise on the left side of the car. I pulled over, lifted the hood and noticed that two of my vacuum lines had blown off and the car was idling rough. I also noticed that around the oil breathers that their was oil that had regurgitated (sp?) on the vented end of the breather. Before I started driving the car the breather was dry and clean.

The previous owner I was told had blown the head gasket 2x, before using some type of copper seal that he said solved the problem.

Please tell me what you think????

 

[dproberts05]

headgasket

Sounds like your headgasket may have let go and pressurized your crankase, blowing oil out of your breathers. The tick you hear may be air being pushed through the section that was blown out.

 

[notacarlo]

Is the tapping only when you load the motor? That may just be an exhaust leak at the header or crossover.

Blowing a vac line is quite common, and recommend that you cable tie or wire wrap those.

the oil out of the breater, may be a PCV issue. Is it the correct PCV valve? - AND these things tend to leak, puke, sputter oil no matter what.

 

[notacarlo]

what dproberts05 says makes as much sense too. I assumed you built the motor after the other owner blew the head gasket.

 

[nick368]

What I'm really afraid of is that when this guy redid the head gasket that maybe he had blown the rings and never fixed those. I have a guy that has been working on the car for me, and has done a fantastic job of putting this car back together. I can't say enough great things about Larry. He is going take a reading on the crankcase tomorrow to check the pressure. The car runs great but when you put a little load on it with the turbo is when this happens.

Any and all comments/suggestions are very appreciated.

 

[notacarlo]

Keep us updated Nick.

 

[nick368]

I hope to know more by tomorrow morning and will update.

Thanks for all of your help

 

[nick368]

UPDATE on Motor Issue

Larry took some compression readings on the cylinders this morning for me:

While I thinkI know what has to happen, I'm curious what everyone else thinks:
Here are the compression numbers after 4 revolutions to the motor

Cylinder LBS.
1 120
2 125
3 95
4 115
5 125
6 120

Your thoughts are greatly appreciated.

Nick

 

[Steve V]

#3 is not good,probably another head gasket. I wonder if the deck/head are warpped. Maybe that's why it keeps blowing?

 

[nick368]

I have decided to have the motor rebuilt. The truth is, the owner had it rebuilt at 129k, but there's no telling what his definition of a rebuild truly is. I know for this car to be done right, I want to make sure that everything is perfect on the car, and not a half a** job. I want a fast GN, but he has to look aesthetically pleasing and run about the same as well.

I will update everyone as to the progress. Thanks for all of your input. The motor is being pulled tonight and started on, on Monday-Wish me luck!!!!

Thanks