Another bites the dust

2012 Tenni V8, 32,500 kms, unmolested, lovingly cared for, Beetle mapped:

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So today I got the verdict from my trusty MG dealer : tappets fucked, cams abrasion, strange mark on holder'.
Will submit evidence and claim to P., should know in a few days.


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Only good news is it is still cold (-2C ~ -9C), wet snow, ice pellets so no motorcycling yet.

One should say something, but it's like déjà vu all over again.

Not good.

None of the flatties are unfortunately.

Was there any reason the MG dealer pulled the cam box at this time; like any symptoms leading to investigation ? I'm running a 2009 one with "goodwill replacement of camshaft" (in service notes) back in august 2013 at 13k miles (before I owned it)...very vague notes in service sheet also says "failed LH side cam all parts"; maybe they did both but clearly wasn't rollerised so just a harder different tappet and same but new running gear. I am doing own servicing and now up to 24k miles (gulp) so just wondering whether to get it checked by dealer (so they can say they found the problem :-)); check it myself and tell them I found it whilst dicking around in the cam box; or ignore it and wait until it goes bad in some way. It seems the problem takes a long time to really hit performance so want to know if there are any warning signs - mine sounds like bag of spanners anyway & makes odd stumble/knock randomly at idle and up to 3000 rpm but still fully usable and its been like that for ages (bit like me).

If the valve clearances open up appreciably faster than expected, if there's an off-idle stumble or it chuffs back through the throttle bodies, it's buggered.

I would take it to a dealer. It seems you have a service history, and it makes a stronger case if a dealer finds it.

I took a proactive approach and actually asked the dealer to check the tappets on my dime and send me pictures knowing full well what was expect . No noticeable noises, rattles clattering other than the usual GRiSO growl.

Just reminded me of something I wanted to share around the why flat tappets fail and see if anyone else out there remembers same - not the answer but a similar problem back in the late 80s (before internet so can't find stuff about it) - I was developing engine oils at the time & mercedes benz had a massive problem with cams & tappets on I think I remember 230E gasoline engines eating themselves away at alarming rate & were looking to oil providers to help fix it short term while long term they re-engineer the metallurgy - I really vaguely remember one possible cause was use of chrome (or similar) on one surface that made it very very hard but at the same time made the 'wetting' (a drop of oil would just stand as a drop and not spread across) very very poor so oil (especially with water in the mix) struggled to cover the surface and as a result even the hard surfaces wore away.....long time & bad memory so bear with me. The problem was really bad but the symptoms weren't obvious until bits had almost worn away completely. As a result MB quietly sent a service note to all garages to replace cams & tappets as a routine in normal service - hundreds per month at the peak ; flush the engine and fit a 'special' oil selected from a factory issued 'grey list' (the handbooks already came with recommended oils on Page 226.1-226.3 but these were failing). The grey list started as observed oils that didn't fail as badly but quickly MB developed a special rig test to qualify the oils. The rig test was called heiss & kalt (Hot & cold) test and simulated cam running in short bursts of very cold then warm then cooling again (I think it was a rigged up partial or whole cylinder head) & I can't remember details of test but vaguely remember had mock blowby condensate or equivalent 'water' tipped in to simulate conditions - if I remember it wasn't a long test (3 days max I think) which suggests it was dramatic failure . The best oils had additive mixtures that helped the wetting and active zddps that responded well to cold and wet. The test became standard at one point until new metallurgy came in.....wish I could find more but back in those days was a paper and fax world....

Thanks Paul, good to know

paulbrice wrote:

Just reminded me of something I wanted to share around the why flat tappets fail and see if anyone else out there remembers same -

Very interesting Paul. I don't know about the oil / metal technicalities, but the situation you relate chimes with my unfortunate 8V experiences in this damp environment and lots of stop-start use and given Pete Roper's observations. The diamond hard coating on later tappets might be analogous to the hard chrome (?) though the original tappets that failed at around 2K miles on mine, didn't have the hard coating – but then they were maybe just unsuitable/ bad quality metallurgy for the job, never mind oil spread.