91 6.2 in a chevy g20 van blew oil...now what

first post...

Hi Everyone!

We are driving a 1991 Chevy G30(?) that was done up to be a conversion van (it was done as new).

The lovely 6.2 l diesel engine runs great but...

1500 miles from home....

Oil was low so I put in a quart, still low, put in another...

Now it was just at the top line.

Drove a few hundred miles with no problem...parked it for a week.

Then drove up over a pass (a low one, 3500 ft but pretty steep at points) and blew oil all over the bottom and dusted the rear of the van with oil. The drip points on the bottom, exhaust hangers had drips, drive shaft a has a sheen on it etc. But when parked no new oil seems to be dripping.

And its only down to half way on the dipstick?

As long as we top it off with oil if it continues to lose it are we cool?

its a bit of a drive home (1500 miles).

It starts right up and great and strong.
No noticeable smoke (this van rarely ever puts out smoke even under power).
Should I get it to a shop right away?

Or can we drive it and pay attention to the levels.

(cash is not really available at present so I lean towards...keep an eye on it
and assume I over filled it somehow and it blew by some seal but is okay now.

Opinions?

Nat

Welcome aboard!

There is NO "drive it and check it" option here. You likely blew, or in the process of blowing, the oil cooler lines. It WILL fail completely before long. If you are driving it at that time, it's game over. Overhaul time (if it's salvageable). Find the leak. Do not run the engine for any period longer than absolutely necessary until you do. It's possible that something loosened up, but you have to find it to know that.

I went under and tried to figure out where it was coming from and from the spatter patterns it seems like this particular oil even came from around the oil filter or maybe the one of the stainless fittings from one of the two oil cooler hoses right next to the oil filter.

Both seem like solidly attached and they are stainless for the run from there to past the spatter so it seems unlikely the hoses are failing but maybe one is cross threaded or something....the van had radiator work done on it in the last year (we just got it 6 months ago). Maybe something got screwed up?

On the other side of the transmission around the starter there seems to be a long term oil leak issue, a good layer of oily gunk, maybe the manifold right there has some exhaust issue plus some slow oil leak but...its a diesel so I'm assuming that's cool...(the phrase I heard was something like... "those 6.2s will stop leaking oil when you stop putting oil in to leak").


thanks for the help!

It may be as simple as the oil filter. Loosen and re-tighten it. Do the same for the oil cooler lines, making sure they are not cross threaded. It wouldn't be considered insane to just replace the oil filter.

If it has SS oil cooler lines, they are not stock, and less likely to fail entirely. Check any areas of connections and abrasion (line resting on something else, unsupported/unclamped).

It may help to use some brake cleaner to clean up the immediate area. Finding a leak will be much easier.

The passenger side is 95% certain a valve cover leak. If it has valve cover gaskets, that certainty increases to 99.9% (should be sealed with only RTV).

A leak due to an overfill is highly unlikely. Normally, excess oil goes through the engine and out the tailpipe. If not, it just makes a big mess on top of the engine (failed CDR plumbing).

I tightened one of the oil coolant hose fittings (the one that was weeping under idle) and drove it around a bit and whatdoyaknow... no more oil leak!

Well, so far at least!

How does a fitting like that come loose? Just vibrations over time? Not tight enough to begin with?

anyway..

thanks for the support!

It seems to be righted!

n

The sun rises. Fittings loosen. It's never not happened. I've told myself I should safety-wire those fittings. After done with an install. And never get back to it. Lather. Rinse. Repeat. Fortunately (unfortunately), the OEM lines will fail at the crimps long before loose fittings become a real thing. I just got in the habit of putting a wrench on them at every oil change.

I hope that ends this chapter for you.

I AGREE 100% with Maverick on the hose thing.

Very seldom do the fittings shake loose..

Usually its the hoses staart leaking at the crimps.

The hoses get soft when hot then harden when cold and eventually they lose the seal within the aluminum crimp fitting.

Every so often you can use an EGR pipe clamp (U CLAMP TYPE) AND FIT IT AROUND THE ORIGINAL FITTING AND SNUG IT UP WHILE THE HOSE IS HOT.

This trick can buy some time.

The only real good fix is a new set of regular hydraulic hoses with the reusable fittings.

They have steel braided layer outside the rubber and then the cloth braid over that.

Very dependable