ALH had been run low on oil... help me diagnose the symptoms that followed?

Ok, the title may make it sound like I know absolutely zero about internal combustion engines, but bear with me...

I bought an 02 Golf from a good friend, who had owned it for six years. It was well maintained. He lowered the car soon after he bought it, and for whatever reason had a knack for finding manhole covers and the like. I think he went through four oil pans during his ownership.

Last time he had it replaced, he told me that the next time he broke one, he was getting rid of the car. So on his way to pick up a friend at the airport a few weeks ago, he hit something going into one of the tunnels on the highway and busted it. Unfortunately, there's not a whole lot you can do while in a tunnel, so he drove through and shut it down asap. He had it towed to the nearest VW dealer, where they put a pan on it, then told him it needed a motor.

I bought it from him, towed it home, and dropped the pan.

#1 bearing showed the most wear...


I put fresh rod bearings in and buttoned it up. I realize that just slapping a set of bearings in a motor that's been run low on oil isn't exactly 'by the book', but I've done this with multiple VW engines in the past, with success.

First start and test drive: it seems to have a misfire at lower revs. Running kind of rough, white smoke and such. After about 20 mins of driving, the oil light came on, but only briefly.

-no noticeable wear on crank journals
-the oil pickup screen didn't appear to be clogged, although I admit I probably didn't look as closely as I should have

I'll compression test it today if I can get some time in the garage... just figured I'd get the ball rolling on here. I'm just trying to figure out what could be causing the misfire and general running like crap. The car ran great before, so I mentally crossed off timing and fuel problems, unless it's an unfortunate coincidence... Ideas?

Worth mentioning: I did start it before I did the work, and it had a noticeable but not horrific knock. That knock is gone, but I would say the top end is a bit more clattery than normal... lifter/cam wear? Hmmm...

Yup, more physical inspection of the top end is in order... but generally the first thing that starves for oil is the turbo...and with clear evidence that the rods ran dry it's pretty possible that the turbo did as well. This could account for rough running and white smoke.. and if the turbo seal really did go south you could be pumping fresh oil into the intake or exhaust.

Standard practice is to remove the hose from the turbo intake and see how she spins manually... checking for slop etc. You can also run the engine (briefly) with the hose removed to see if the turbo spins. A boost gauge or VCDS tool would be another way to check for proper turbo function.

Vince Waldon said:

Yup, more physical inspection of the top end is in order... but generally the first thing that starves for oil is the turbo...and with clear evidence that the rods ran dry it's pretty possible that the turbo did as well. This could account for rough running and white smoke.. and if the turbo seal really did go south you could be pumping fresh oil into the intake or exhaust.

Standard practice is to remove the hose from the turbo intake and see how she spins manually... checking for slop etc.

Click to expand...

Thanks. I'm hoping I can get some time to dig into it this afternoon. I'm a newbie when it comes to vnt's... if it feels tight, is it safe to say that it's still ok? Or could there be other problems with the turbo specifically?

As far as top end inspection, I'm assuming I'm just looking for anything that doesn't look "right". I'm told that ALH cams have a shorter lifespan than the older diesels? Am I supposed to be able to tell if it's ok by just looking at the lobes? Or measuring?

Yup, don't let the fact that it's a VNT spook ya...that's just the control mechinism on the exhaust side. The rest of it (and particularly the part that could have been oil-starved) is just standard turbo on oil-floated bearings spinning at 100K rpm ... so you're looking to see if the impeller still spins freely, has any in-out "slop" in the shaft you can feel, or any more than an impression of up-down slop.

Top end damage should be fairly obvious on visual inspection with the valve cover off.. cam lobe or hydraulic lifter wear, signs of galling, etc.

Side note: I found this when I dropped the pan, which caused me to soil my pants...



Until I realized it was from here. Apparently the highly qualified VW tech used a bolt that was too long, and ran it in with an impact, or something ridiculous. Half the oil pan bolts were loose, and half of them were stupid tight. Top notch work...

check the number one cam journal for galling

You renewed the rod bearings but not the crank bearings?
New crankshaft bearings will likely restore the oil pressure.
The bentley says to replace the oil cooler when this happens, not sure why. When this happened to me, there were a lot a metal flecks.

Metal flakes would have been filtered at the filter...

I'd set up a mechanical oil pressure gauge at the filter housing temporary to check oil pressure.. Screw out the electrical sender and screw in an adapter for a gauge.

Like this ........... slightly warmed up engine (below)



And, like this ........ fully warmed up engine (below)




Many times, Main Bearings will survive while the rod bearings don't as can be seen in the OP's pic. However, I'd be inclined to drop the pan again, closely inspect the oil pickup screen for particles and also drop a main bearing cap or two for inspection. As I recall, those bolts can be re-used.

And, as suggested by Vince, the Turbo most likely suffered as it was definitely supplying boost as he drove it out through and out of the tunnel.......

And, definitely check the cam journal caps as Jimbote pointed out...

Ew...



Now what??

Depends on how long you want to run this engine.

'Twere me... if everything else is repairable I might live with the scarring on the cam bearing... there's lots of area left.

That said, if you know a good machine shop the bearing cap can be shortened and the cam bore re-bored.

Turbo's still the big question in my mind.. and if it's broke you're now looking at some repair dollars that may make you question the whole engine's viability, investment-wise.

Actually, that looks pretty good..........

What do the Cam journals look like?

AndyBees said:

Actually, that looks pretty good..........

What do the Cam journals look like?

Click to expand...

the upper always looks better than the lower ... most of the damage will be to the journal under the cam ... pull the cam and have a look... there will also be aluminum transferred to the cam itself you can usually clean it up with a pick or muriatic acid

Update:

the turbo seems to be ok, from what I can tell. Shaft spins freely, with minimal side to side movement but no in/out. There was some oil in the intercooler piping, but not a lot.

The cam journal that I'm looking at looks good. No foreign material. I think I'll pull all the caps one at a time to make sure it's not awful, but I'm gonna try to hold off on pulling the cam for now.

Next step is to drop the pan again and check the pickup screen.

From bad to worse.

Spun main bearing and cap next to a good one.



Yikes.



Looks like I'm on the hunt for a good ALH block... or parting it out.

the reason the lower number one cam journal takes the biggest hit is because it has the greatest downward load from the very tight timing belt .... just removing the caps only reveals the least amount of damage ... good luck !

Or get that cap machined and that journal bored.

Don't do this at home...... Quick story..

In 1995 I purchased for cheap a very high mileage 1990 Toyota Tercel with the little 1500 engine. About a year later, one of the rod bearings spun..

I dropped all the rod caps and installed new bearings. On the rod that spun the bearing, I sanded down the bearing cap where it mates to the rod so it would fit closer/tighter, roughed up the backs of the bearings, and used lock-tit on them.

The engine was still running when I sold it in 2003 ..... (smoked a little for 370k miles)

AndyBees said:

Don't do this at home...... Quick story..

In 1995 I purchased for cheap a very high mileage 1990 Toyota Tercel with the little 1500 engine. About a year later, one of the rod bearings spun..

I dropped all the rod caps and installed new bearings. On the rod that spun the bearing, I sanded down the bearing cap where it mates to the rod so it would fit closer/tighter, roughed up the backs of the bearings, and used lock-tit on them.

The engine was still running when I sold it in 2003 ..... (smoked a little for 370k miles)

Click to expand...

Ha! That's fantastic. At this point, I'm leaning towards finding a block. I'm in the car pretty cheap, it's in good shape overall, and I'm hoping to keep it for a while.

Smokin' Dually said:

Or get that cap machined and that journal bored.

Click to expand...

you would have to machine all the caps and have the entire head line bored ... just machining the one cap and bore would force the cam to bend down on the end... you could machine the one bore/cap to accept a repair sleeve

Jimbote, what about the spun bearing damage to the Main Bearing Cap?

Is that fixable?

AndyBees said:

Jimbote, what about the spun bearing damage to the Main Bearing Cap?

Is that fixable?

Click to expand...

yes, but not worth it in my opinion because line boring moves the crankshaft up in the block, this changes the cranks relationship to both crank seals, it changes piston projection, and it changes crank centerline to transmission centerline ... it opens up a huge can-O'-worms...i guess if you machined that one journal and resleeved it it would be ok ... but blocks can be had so cheap why bother ?.... pretty much same story for the head although not as many worms to deal with

^ exactly. Which is why I'm shopping. It just isn't worth the money to fix this block.