Dennis Gentry, August 15th
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Greetings,
Some of you may remember me as the guy who slapped a new Mark Stephens engine in his '80 Vanagon and headed off to Inuvik. Well, I made it to Inuvik just fine, and am here in Fairbanks after the splintering of the group in Tok.
Ever since I left I've had this uneven idle that I was chalking up to a vacuum leak. The VW dealer in Prince George couldn't find it, but confirmed that the vacuum was 7" instead of the 14" that it should have been. After assurances that I was running rich enough to avoid burning a valve, I pressed on with the group to Inuvik. (The engine still seems totally smooth and peppy, except at idle--quite nice to drive.)
When I finally rolled into Fairbanks (Ah! Civilization and Pizza Hut again!), it occurred to me that there was a VW dealer here. Still slightly irritated with the mystery vacuum leak and rough idle, I decided to take it in and let them look for the vacuum leak.
The VW dealer here in Fairbanks said my compression was 75, 125, 125, 125, with the low cylinder coming up to 125 with oil, and wanted to do a teardown to replace the faulty cylinder/rings. I almost went for the estimated $1,500 teardown, but thought I'd check it out myself first. Lo and behold, I came up with 110, 120, 120, 125--not perfect, but definitely not immediate teardown time. I can't decide whether the dealer mechanic is dishonest or incompetent or what. On one hand, I'd like to give them a chance to explain; on the other, I don't really want them anywhere near my bus now. No wonder they were able to get me in right away--the locals have figured out that it's a terrible shop.
Friends here in Fairbanks recommended Midnight Sun Auto & Truck Repair as an honest bunch, so I took it in to the place, which is surrounded by domestic pickups and tractor-trailer rigs. I wasn't expecting much VW expertise, but was surprised to learn that the guy who was going to work on it owned an '80 vanagon from '80 to last year, so I'm pretty sure he's familiar with it.
Well, he checked it out and says that there is a compression leak on the suspect cylinder, and says he can feel it at the cylinder-to-head mating, having removed the lower engine tin. BTW, his compression numbers agree with mine pretty closely (percentage-wise, not absolutely). Oil in the cylinder doesn't bring the compression up more than a pound or two.
My first question for the experts on the list is: Would a head-gasket leak like this cause the low vacuum that we've measured, and thus cause the rough idle? Or should I still be trying to track down some other source for a vacuum leak?
Also, what is the likely cause of the compression leak on such a low-time engine? I'll be calling Mark Stephens tomorrow to see what they have to say, but it seems to me that they must not have torqued the head bolts correctly, or one of the studs is pulling out of the case already. I had something similar happen after a head replacement on my '72 bus by a normally excellent shop in Seattle--I never figured out what the problem had been, but put in a new head gasket over a tiny bit of erosion on the head and drove happily for another 20K miles so far.
Other than the obnoxious vibration from a few washboards on the unpaved bits of road, I've been pretty easy on this engine. Should I just torque it up (to specs, I mean) and limp back to California? Pull the head and put in a new gasket if the erosion isn't too bad and then limp back to California? The shortest route I can figure is about 1500 miles and involves a $700 ferry ride (which would be partly worth it just for the relaxation and scenery value).
Any advice appreciated,
Dennis in Fairbanks
P.S. Surmountable mechanical problems or not, this has been quite an amazing trip. It was fun traveling with the other Top of the World Tourists. Maybe I can find Sue from Ohio here--I heard she's here in Fairbanks.
P.P.S. I've read of re-torquing the head bolts on a fresh rebuild at 100 miles (with the engine cold). But the literature that came with the engine didn't mention anything about that, just the break-in oil changes and how to adjust the hydraulic lifters, in the unlikely event that that was necessary. Someone I talked to said the re-torquing applied to older engines. I think on '72s and later you have to at least remove the rear engine crossmember and lower the engine/transaxle a bit to get to all of the head bolts, so retorquing would be a bit of a pain.
