Author Topic: A Few Issues At Once (Read 7041 times)

Methanolab · « **on:** March 15, 2008, 12:57:06 pm »

Hey All,
I got a couple problems and need some help if you please.

Vehicle: US 1983 VW Quantum 1.6 TD Wagon 235K mi. Averages 42 mpg 0.5-1L oil consumed/leaked every 400 mi.

I have put 100 miles a day on this car since I bought it two years (55k mi) ago. I took it on a 1500 mi trip two weeks ago and noticed fuel mileage down to 35-38 mpg. And increased oil consumption/leakage. About 1000 miles in it started idling really rough and oil consumption went up to 1L per 100 mi. It is leaking much more oil but I don't know if it is consuming more as well. Above idle it runs fine, maybe a little lack of power. It is very hard to start and sounds like it is rattling when I turn it over, the whole thing shakes. It turns over faster with the cold start lever pushed in and that is the only way it will start. While giving it fuel and with the cold start lever in, it takes a half a minute of cranking to get it to start and it lets out a larger cloud of dark smoke than it used to. Then it runs roughly and doesn't seem to respond very quickly to the accelerator for a minute or two.
I checked the glow plugs and they are conducting electricity. I loosened the fuel injector unions one at a time at fast idle and each one reduced the motor speed the same. It made an 8 inch puddle of oil in 1/2 to 1hr of idling, about a drop a second from the oil pan. Once the motor warmed up the idle smoothed out a little but was still rougher than normal. I raised the idle adjustment so it idles smoothly now and doesn't seem too fast. The idle has always seemed too low. The motor used to shake before I replaced all the mounts about a year ago. They couldn't have gone bad again already could they?
I imagine I am loosing some oil from worn rings. I meant to check the compression after I bought it because of age, miles, and oil consumption but it ran so good I didn't bother. Obviously I have a bad oil leak now, maybe crank shaft seal? I will need to clean the whole motor compartment again to track it down. My dipstick tube seal (replaced a year ago) might have gone bad again? I suppose blowby and crankcase pressure might be making it worse.
Could lack of compression be making it so hard to start and causing the rough idle and oil consumption/leaks? Or poor spray pattern from the injectors? Does it sound like there is something wrong with the cold start system or the injector pump? I get an air bubble cruising down the fuel line to the pump every once in a while but it doesn't seem to effect the motor. Sorry for the long tale of woe, I know there are some real gurus around here. Any help would be greatly appreciated, I love this car. Thanks,
--Chris

jtanguay · « **Reply #1 on:** March 15, 2008, 01:13:49 pm »

since it has mechanical lifters, you should probably adjust the valves. they *should* be checked every 15'000km's or so. or is it miles? all you need to check is a feeler gauge that you stick between the cam lobe and the valve lifter when the lobe is pointed up.

rough starting, crappy idling, bad fuel economy, and eventually a no-start situation can occur. the oil consumption could be from bad valve seals or stuck/worn rings.

hope that helps!

Methanolab · « **Reply #2 on:** March 15, 2008, 01:24:04 pm »

Thanks, yea I check the valve shims faithfully every six months or so. I need to do that again now. It would be nice if that was all that was wrong. I have never had to make any adjustments when I checked them in the past. I really hope its not the rings. Thanks

jtanguay · « **Reply #3 on:** March 15, 2008, 01:27:00 pm »

if you could check the compression that would give a good idea of what might be going on. i bought a kit off ebay that was cheap, but looks to be of decent quality.

Methanolab · « **Reply #4 on:** March 15, 2008, 02:48:31 pm »

I will do that next. I hope to have a chance in the next week or so. I have been very busy lately. If you think of it, please keep an eye out for the results. Should be within two weeks.

Patrick · « **Reply #5 on:** March 15, 2008, 04:09:44 pm »

I'd be looking at the timing and the fuel filter if it was mine, as well as compression.

Possum79 · « **Reply #6 on:** March 17, 2008, 10:26:23 am »

If you get a compression tester off of ebay dont spend more then 24.99. I looked at them once and went hey thats the EXACT same kit you can buy from harborfreight.com for 24.99. Only ebay has then for like 29.99 and 18 to ship. Check harborfreight.com before you buy. May save a few bucks for the same kit.

I bought one from harbor but havent used it yet.

zukgod1 · « **Reply #7 on:** March 17, 2008, 10:37:37 am »

Quote from: "Possum79"

If you get a compression tester off of ebay dont spend more then 24.99. I looked at them once and went hey thats the EXACT same kit you can buy from harborfreight.com for 24.99. Only ebay has then for like 29.99 and 18 to ship. Check harborfreight.com before you buy. May save a few bucks for the same kit.

I bought one from harbor but havent used it yet.

Bought mine from there, used it a couple times now. Seems to work fine.

Methanolab · « **Reply #8 on:** April 05, 2008, 06:58:16 pm »

Finally got to work on it today. First I checked the valve timing and the crank timing. They were pretty good but I tightened the belt (its due to be replaced). Then I checked the injection pump timing and it was at 0.80 instead of 1.0 +/- 0.07. I adjusted the pump timing. The valve clearances were all good. It started a little better but was still sputtering a little rough and smoking. I changed the fuel filter and filled it with ATF and that just about got it back to normal. Later I ran a can of injector cleaner and more ATF through it. Seems to be running pretty good now. Still has a decent oil leak but I don't know if it is any worse than it used to be.
Next I am going to clean the motor and try to find where it is coming from. It looks like the valve cover, the oil filter seal where it connects to the block, the dipstick seal at the block, the front main crank seal, and maybe the oil pan seal. There is also an exhaust leak at the manifold. Didn't get to check compression but I still hope to. Is there a good thread or sticky around on a crank case ventilation modification? That might reduce the pressure on the oil seals wouldn't it? The pressure at the oil fill hole seems to have gotten stronger in the last year. It blows a heavy rag now. Thanks for your input.
--Chris

Methanolab · « **Reply #9 on:** April 17, 2008, 03:18:38 pm »

Ok compression results, read 'em and weep: (with me)

PSI / +oil
1: 375 / 600
2: 225 / 595
3: 375 / 475
4: 30 / 175

Possum79 · « **Reply #10 on:** April 17, 2008, 04:38:38 pm »

I weep for you :cry: . I still have yet to check my compression. I have new nozzles for my injectors and i want to do it all at the same time but i have yet to build a pop tester.

Im scared I may end up with horrible results.

Time to re-ring her bud.

Methanolab · « **Reply #11 on:** April 23, 2008, 06:42:24 pm »

What do you all think, should I rebuild it, sell it, part it, junk it, rebuild the motor for something else and junk/part the body?

Possum79 · « **Reply #12 on:** April 24, 2008, 08:38:05 am »

To me it depends on what you need. If you like the car and want it rebuild and reuse. If you dont sell stuff out of it.

jimfoo · « **Reply #13 on:** April 24, 2008, 08:44:06 am »

Rebuild it. If you sell it for something else, who's to say you won't have to soon do work on it? If you rebuild it, you know everything is good.

jtanguay · « **Reply #14 on:** April 24, 2008, 09:26:49 am »

Quote from: "jimfoo"

Rebuild it. If you sell it for something else, who's to say you won't have to soon do work on it? If you rebuild it, you know everything is good.

i agree... what if its just a valve that isn't seating properly? get the head professionally done or just buy one from www.dieselvw.com with new valves and lifters, and then buy new rings for the pistons. might not need to bore it out.