Trouble in TN, VW Diesel (non-MB)

[wolf_walker]

I flew out from NC to OK last Saturday morning to retrieve my trusty old 81 Caddy, father had been using it the last couple years while he tinkered on putting the 1.9 in his 82.

I set out, things went ok, gearing in the new gasser trans is pretty decent, cruise control works alright, everythings groovy.
About 50 miles west of Lebanon TN, crawling along in 1st in traffic, I hear TANG, CLACK CLACK CLACK, pull off and shut it down. Visual shows nothing wrong, fire it up again, cursed, and limp up an offramp to a hotel parking lot. Run it some more, listen more, decide I'm screwed.
Called father and talked it over, decided to drive it around the hotel a little more, and the sound went away. I says to myself "well darn".

So. Something got into/broke off in the combustian chamber, and it's a damn miracle it didnt hole a piston or something. I drove the rest of the 800 or so miles home and didnt miss a beat. It does have a funny "hop" at idle, it's subtle, but it's there. Smoke and power are ok pretty much. Cold starts fine, cold as it is anyway. About all I can figure is a glowplug tip broke off maybe, but seems like it should have been hard starting or the light should have accted funny, but maybe not. Till I can get some heat shields here and start pulling stuff and smoke the business end over, I'm going to keep driving it.

Anyone ever had a similier experience/noise? It made a hell of a racket.
First time a VW diesel has ever let me down(almost). And I have a lot of miles on them, this little truck is at almost 600K now. 41mpg running 70 on the interstate BTW.

Another note, father said it started running bad in the last year, much smoke, no power, he stuck some new injector nozzles in, cleared it right up. He did not have them pop'd to check pressure though, but it ran alright. This funny idle it has now goes away with even a slight bit of throttle. I've felt a diesel do this exact thing somewhere, but I can't remember when/what/where.

Lord I've missed a VW diesel, the Mercedes and BMW were just not the same.

And I also rode in an 05 Jetta TDI and saw it pull to 125mph like nothing. I was impressed with it's top-end. Handled like crap though.

[rs899]

I know what you mean about VW pickups. I have one out in the parking lot now with 500 lbs of concrete in it. I will probably sell it soon or morph it into a VW Cabriolet diesel as I have a full size truck.

You have 600K miles on the engine?? I don't think mine will last that long . It has 120K miles on its last rebuild and its burning some oil.

As for your problem, I suppose a glow plug could be it, but I think you would notice it starting harder. It may have been a chunk of carbon on the glow plug that came off. You will probably never know until you pull the head.

Rick

[barry123400]

The chunk of carbon ideal brings back memories. Never had it happen with any of my vw diesels over the years but always a first. Can sound like the engine is on the verge of comming apart though. Also would answer why it went away. Unfortunatly does not explain the resultant odd idle left over. But perhaps a valve got bent a little in the process and is not sealing really well anymore. judging by the noise the carbon is pretty hard and since there is no give in the earlier vw valve trains with mechanical lifters perhaps a possibility? Now if a glow plug tip got in there (not sure if it is possible) could perhaps have damaged a valve in simular fashion as well. The main point and upside I believe is that serious problems (rod bearings, wrist pins, pistons.) do not cure themselves. Since you drove a long way after the primary event I assume the timming belt did not move a cog or two but you may want to check cam to crank timing as its pretty easy to do. You might try to establish the marginal cylinder and inject air at tdc to see if one valve has leakage. A few of us here drive the older jettas on an almost continious basis and we have never had a carbon problem of that magnitude but you have a lot more miles where our limiting factor is the rusting of the bodies. We almost never see more than 300 thousand miles total per car and even that is the exception here.

[wolf_walker]

I've been mulling the carbon idea over, makes sense. The last two years father's had it, she's had progresivly worse injectors, much smoke, good for building carbon. Damn shame. Guess I need a compression/leakdown test.
crap.


It has a few small rust spots now that were not there a few years ago. I can fix them, but it'll always just be a beater due to an accident long, long ago. A lot of it is still in better shape than most anything with the mileage, especialy that was never washed, driven hard, used as a truck, etc.
It's good to come home. I've sure missed VW's..

[t walgamuth]

could have dropped a tip off the glow plug and bent a rod. i did that on a 6.2 chevy diesel. a large blob of carbon could do it too. the hoppy idle can be due to low compression in that cyl caused by shorter stroke from bent rod.