Dang it!

[Russell]

Stupid 89... Its been leaking oil, but apparantly last night, I lost a lot more oil than I had been, got to school with a few low end knocks, which I thought was a bit unusual, but figured that was just bad gas as I just filled it up. Got out after school, and the truck started rough, and was knocking really badly until I got the RPMs up. Winds up I leaked enough oil that it wasn't making any pressure in the low end anymore. I drove it home slowly and carefully, but I'm a bit worried about it. I only drove about 5 miles home, but how much damage could have been done during that time? As soon as I got home, I poured fresh oil in, and the knocking went away, but it definitely seems to have lost some power. My oil isn't looking like a milk shake, and neither of my pipes are smoking white, so I don't think I blew a headgasket (running without oil probally makes things rather hot!) but I'm worried I may have glazed the cylinder walls.

Any thoughts?

PS -- The truck is getting a new Fel-Pro single piece pan gasket tonight, and a fresh change of oil. I'll be watching for sparkles in the oil

I hope I didn't wipe my cam out, cause that'd be a really sucky job in this truck...

[Lynx]

not sure about glazing but id cut open the filter and look for metal in the pleats.

[Zilverado]

I don't know how much damage you could have done (especially if it's a performance engine), but the one thing I do know is that these engines are almost impossible to kill. I used to have a '77 with a 305 that would register zero oil pressure at idle - that's right, the needle bottomed out. I could hear the main bearings clunking away, and still the engine ran nice and smooth, started easy and didn't burn significant oil. Continued to run great until I retired the truck a couple of years later.

Not that I'm suggesting you shouldn't be concerned, but I'm sure the engine is not completely spent. Unless, like I said, it is a performance engine and the damage done (even if minor) robs you of horsepower.

Just my $.02 - - hope all is fine.

[Russell]

Its not a really high performance engine by any means. Just a 355 with some flat tops.

I think it'll be ok, but we'll see how it goes this afternoon. Just spent 100 bucks on the pan gasket, oil, filter, and exhaust gasket to fix that exhaust leak that is making the truck run rich (leak is upstream of the 02 sensor, giving a false lean signal) which dissolved my pan main gasket, which caused a massive leak that caused the engine to loose oil pressure.

Stupid little exhaust tick...

[454HO]

Since you are pulling the pan anyway, why not pull one of the main bearing caps and check the bearings for excessive wear? Maybe a conn rod cap too? It should be pretty obvious if they are toasted. If they are, and you ignore it, you could end up spinning a bearing which could potentially trash the whole engine.

[Russell]

Exactly what I just did. What does a guy look for as far as a worn out bearing goes? The one I pulled looks fine to me, but I may be missing something.

There was a small amount of glitter in the oil, which smelled more like gasoline, than it did oil. I dunno if that is left overs from the oil I dropped out of the 89 though, it was pretty shiny stuff. I cut the filter open, and it didn't look half bad at all, a fair bit of carbon in there, but no significant amounts of shiny stuff.

So long as nothing overheated, and cracked, I think I'm gonna be ok. The reason why I worry about overheating is that my temp gauge doesn't work, and I didn't have my laptop with me this time around to keep an eye on the temps (has a digital dash board that tells you your MAP readings, speed, rpms, coolant temp etc)

[454HO]

Originally Posted by Russell

Exactly what I just did. What does a guy look for as far as a worn out bearing goes? The one I pulled looks fine to me, but I may be missing something.

I would look for obvious discolorations or wear. You might do a search for engine bearing wear and find some photos to compare to. Hopefully you got lucky and they are fine.

[Russell]

Well, I think I am gonna be ok here. None of the bearings had any discoloration, or obvious wear to them. They all looked like they were just put in there yesterday.

So, I gotta wait for my new pan gasket to arrive (4 -> 6 days) then I can put it together, and see if its alright.

All of this caused by a little exhaust leak, lol

The truck is TBI injected, and the exhaust leak was on the manifold to head connection directly above the 02 sensor. It was detecting a lean condition constantly, and was directing the computer to pour a crapload of fuel in. Doing that caused nasty fuel vapour blowby into the crank case, which made the oil very thin, and also corrosive to the old cork pan gasket. So, it ate through the pan gasket, and started leaking something terrible when I ran the truck / just after I parked it after driving. That caused all the oil to spill out, and what little oil that was left was gas drenched (smelled more like gas than oil) and was useless for lubricating.

[454HO]

Since it's going to be a couple days before you get the gasket, you might want to get some plastigauge and check your bearing clearances. More cheap insurance.

[Russell]

Midas well, what is involved in that process? Got any links? I've never built a bottom end from scratch before. This was my first time pulling off a main / rod cap on an engine I planned on using again, lol! Torque specs are 65 ft lbs on the inners, and 60 on the outers correct? Thats what my haynes book said, but I don't always trust it, lol

[iceman7329]

Torque specs can be found here, http://www.freewebs.com/myprojecttru...trucksinfo.htm near the bottom of the page, the site name is really www.87gmc.tk

[Lynx]

To use plastiguage you gotta have a spec on what the clearnce is. Once you got that you find the right size piece, put a strip on the bearing, put on your cap and torque. Take the cap off and line up the now squashed strip with the gauge on the plastiguage packedge. That will tell you the clearance that is there and if the bearing has worn and if you have the right size bearing to start with.

[Russell]

Ok, that sounds fairly simple, I'll get some, and try it out tommorow night.