

| Subject: | Re: Diesel head gasket blown? |
| From: | Doktor Tim |
| Date: | Fri, 19 Sep 2003 20:12:00 -0700 |
At 08:50 PM 09/19/2003, you wrote: >Hello, > >Some of you are aware of the fact that I blew a hard-to-find radiator >hose about a month ago, and I still don't have it's replacement from >VOA. I think Ron at Bus Depot has later hoses. I have a client with an 83 and when needed, I will convert it to the later hoses. >That made me think that there might be a head gasket problem, and if so >that is probably what blew the hose in the first place. > >The engine starts a little rough but seems to run OK, it's the first >diesel I've ever messed with so I'm not sure what's "right." > >Anyway, what else should I look for in the way of blown gasket symptoms? From a cold start let it idle for 30 seconds, then twist off the cap and see if there is any pressure. There will not be any pressure from heat build up so any pressure will verify combustion leakage pumping pressure into the coolant. As this progresses it starts pumping coolant past the cap into the overflow tank and overflowing and of course, overheating. By this time you should see air bubbles and/or froth in the pressure tank. >If it is a blown head gasket, what's usually involved in fixing them, >and how much does it cost to have a shop do it? The last Vanagon Diesel head gasket I did was around $900. That included scraping and cleaning very well the head and block surfaces, applying Kopper Kote to a new Elring gasket, and bolting it back together with a $160 set of high tech studs and nuts to replace the bolts. These were torqued in three stages to spec, run to operation temp, then retorqued. At a thousand miles of use, per Bentley and the instructions with the spezial studs, I will retorque them one more time. It also included 2 gallons coolant, oil and filter, and a chunk of change for the government. Jerry at NW ConRod (40+ years VW motor machining and assembly experience) has advised that some of these motors have repeat failures for no good reason, assembled per Bentley, and these extra steps will nip this rare but not rare enough repeat failure problem in the bud. Now here is one on Bentley. ANNOMALY ALERT--ERRORS AND OMISSIONS These diesel motors used two types of head bolts. The Bentley does acknowledge both 11mm type standard bolts and the 12mm torque to yield bolts. Then it goes on to give the procedure for the 12mm bolts. But they do not give the torque specs anywhere for the 11mm standard staged torque bolts. Use three stages 30/50/65 lbs for those. That is also the spec for these high tech studs and nuts. Also, if you have the 12mm torque to yield bolts, they don't give the maximum length of the stretched bolt for reuse, so you must replace them with new or risk failure. So I have these 11 mm bolts that are just perfect for making pairs of alinement pins for reinstalling the gasket and head which you simply must have or you WILL bugger the gasket and spray sealant film trying to get a bolt started. Instant re-failure is not the way to finish this job.
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