99 EVC with 260,000 miles, I bought I new and have kept it pretty well maintained.
At 245,000 miles I had a VW dealer top end rebuild, timing chain tensioner went and we ended our vacation a little early.
I have noticed that rattling sound that is familiar to VR6 owners signaling a timing chain rails and tensioner work. Which seems really early and leads to my questions:
1. 260,000 miles I imagine that there has been a drop in oil pressure, and although I do not have a low oil pressure light on I was wondering if the oil pressure could be low enough to effect the pressure of the hydrolic chain tensioner and not give a low oil pressure light?
Specifically what should my oil pressure be to keep the hydro chain tensioner working properly?
What does the oil pressure have to dip below to give a low oil pressure light?
Open to any other suggestions regarding a timing chain tension, rails, and timing belt issues after only 14,000 miles?
Thanks for your support,Jimmie
99 should mean the later AES with the simplex chains. The top tensioner is spring loaded with hydraulic assistance. No way your pressure goes so low to disable the tensioner. I would check the sliders that tensions the chains. This can be checked by removing the upper right side cover.
First, let me say, Indian has far far more experience on engines than I will ever gain, I am only a shady tree mechanic and have only worked on the AXK (2001-2003 engine in my Euro. That being said, I did my timing chain with 126k miles on it, the engine has had great maintenance with very regular oil changes. There was very little wear on anything, however I suspected the upper tensioner to be the actual issue, I could be wrong, although the guides, all looked great with almost no wear at all, and the chain appeared fine-I will never know, I replaced all the common wear parts. In the process, If you look at all the threads in several forums on VR6 engines (AES being one also) it is required to prefill the tensioner, and oddly some folks have the ill fated chain noise reappear almost immediately, I have wondered if this is due to the tensioner not being prefilled during the job, and thus causing premature; wear on the tensioner. Although it has a spring, they do not add the hydraulic for no reason, and I wonder if this could contribute.to the premature sporatic failure. Only speculating. Also, I will say, if the dealer didn't replace all the parts-guide etc(which I cannot imagine) that would explain all. The upper oil tensioner is easy to replace in the AXK, and I imagine in your AES as well and is only $77.00. if you go that route, prefill it. I would also first consider checking the oil pressure- not sure of the best way to do so, but I am sure many have an idea of how to do so. With 260k mi on the engine, depending on oil changes and type oil as well, I would think the oil pressure could be poor anyway. If needed, replacing the oil pump (at least on the AXK ) is not that bad a job to access, though not a fast proceedure to remove & get access to the oil-pan-one axle removed?, but not that bad either. Please let us all know the outcome.