87 Grand Wagoneer Blowback issuses with Oil cap

halfsight · 11-18-2009, 06:23 PM

Ok so I am new to the Jeep world *about two weeks old new* and I'm afraid I've made a mistake in my choice. 2 weeks ago I bought a 87 Jeep Grand Wagoneer 360 V8 with 114k miles on it 2 owners for $600.00 (from Family). The Body and Interior are spotless and seemed to have been really taken care of. When I bought it I was told it leaked a small amount of oil and that the oil cap and hose leading from it to the air filter were loose and needed to be replaced which I did for a couple of bucks. A couple of days later I noticed that it seemed to Idle High and that it was smoking some but checked everything I new to check and it seemed fine so I thought since it had'nt been driven in a awhile it might stop after driving it for awhile. The the other morning my wife took the jeep to school *about 30 miles away* and called me once there and told me the Oil pressuse gage and started bouncing from about 70 to nothing on the way and when she poped the hood the brand new Oil cap and hose had blown off from both sides and was sitting on the engine. she try'd her best to place it back on and drove to a near by mechanic only to find out the Cap had blown apart and lost all its packing and that the hose was also now shot, he said the engine was causing massive blow back and that there was something major wrong and suggested that if she ever wished to drive it for over 30 miles she needed to have the entire engine rebuilt. Now I know next to nothing about jeeps or carberated engines but I have never heard of this and cant figure out what could be wrong but I do know I dont have the money to rebuild this engine and I'm not even sure if I would need to. I was just wondering if anyone has ever had this problem or even what it might be and what might need to be done to fix it. I would hate to get rid of it as I have fallen in love with the beast but if its too major an ordeal I might not have another choice. Any help would be thanked and I fiigured this group would be the best first place to ask.. Many thanx
Case from Ellijay Ga

WaveHunter · 11-18-2009, 09:08 PM

A clogged PCV valve could cause some blow-by but I don't know if that bad. But you never know. The manifold hole for the PCV grommet can get gunked up as well. It could be rings like the mechanic was hinting at, but maybe not. Do a wet & dry compression check and that should give you a better idea of the condition of the rings.

Even needing a rebuild you still got a pretty good deal with the nice body and interior. After you have it for a while you will fall in love with it.

CutterN55 · 11-19-2009, 10:08 AM

Quote:

Originally Posted by WaveHunter

A clogged PCV valve could cause some blow-by but I don't know if that bad. But you never know. The manifold hole for the PCV grommet can get gunked up as well. It could be rings like the mechanic was hinting at, but maybe not. Do a wet & dry compression check and that should give you a better idea of the condition of the rings.

Even needing a rebuild you still got a pretty good deal with the nice body and interior. After you have it for a while you will fall in love with it.

I was thinking the same thing on the PCV, though it seems like a LOT of pressure to blow the cap apart. $600 bucks for the truck, even buying a rebuilt stock engine for $600-$1000 you'd still have a great Jeep for $1600. Ask around on International Full Size Jeep Association. Some body on there will know something or be able to get you a motor if you need it.

WaveHunter · 11-19-2009, 01:25 PM

Quote:

Originally Posted by CutterN55

I was thinking the same thing on the PCV, though it seems like a LOT of pressure to blow the cap apart.

I agree, and the cap should be vented to the air breather anyway. I'm not sure how it could happen, all I can do is guess.

Patriotic_Giant · 11-20-2009, 07:48 PM

In 2003, I had a " Mechanic " in Boston tell my g/f that our '94 Nissan pick up was on it's last legs and would require " XYZ " in the immediate future.

We drove the truck to our new home in Florida later that year, and kept it on the road until two years ago when I sold it locally......I still see it on the road every now and again, in town.

Since the garage visit in 2003, I replaced the starter........last leg? yeah right!

halfsight · 11-21-2009, 03:30 PM

Status update:
After my wife got it home I finally got a chance to look it over and heres the deal as far as I can tell. The cap didnt "blow apart" as she was told but the packing *PCV filter in oil cap from what I can gather?* is gone which is odd since the oil cap is only 2 weeks old. The Oil pressure does bounce for some reason but the jeep acts like nothing is wrong... it actually idles better than it was before all this. I going to be doing the vaccume test thats in the Haynes manual later on plus I was told that since the Jeep sat for awhile that sludge in the Oil pan could also cause odd pressures and the such so I'm going to be removing that and checking it as well. I want to thank all of you for you're help so far, I had always heard about the loyalties of jeep owners and you guys have proven it.. thanx again and I'll post back the results and check to see if anyone else has ideas as to what this could be