Bought a used TDI, I think wrong oil has been used

Hi there,

I bought a used TDI with a BEW engine. The car also had a fantastic service history, with regular oil changes every 5k miles or so. The receipts say that the oil used the entire time has been Mobil 1 Synthetic 5w-30. This worries me, as I don't think that's on the approved oil list and may not meet VW 505.01 spec.

The car is sitting at just over 130k miles, and I don't think that the camshaft has ever been inspected. It runs beautifully after replacing the alternator pulley, and it only has occasional, extremely minor hiccups at idle, much like I've felt on almost every other car I have driven. I have no abnormal noises coming from the engine, either.

I have since switched to Liquimoly Top Tech 4100 5w-40. Do you think it would be necessary to pull off the valve cover and take a peek at the camshaft at this time?

I would change the fuel filter for the hiccups but I would leave the valve cover alone especially if the car was well maintained.

if its M1 ESP 5W-30 its 507 rated which exceeds 505 spec.

If it were mine, I'd inspect the cam just because it would be part of my new car bonding. And now that it's yours, you can stop the 5k mile oil changes!

Couldn’t hurt to pull the valve cover and check the cam. I’d stick with the 5w40 but the 30 weight shouldn’t have hurt it.

Your fine. Fill up with what you want to motor on. If your paranoid, spec out the cam with a dial caliper, and do a compression test and put an oil psi gauge on it and see if it all falls in spec. But again, that's over kill

My dearly departed '05 BEW went 240K mi on Mobil 1 5W/40 TDT with 10K oil change intervals. Since 37K mi when I bought it anyway. No significant wear on original cam at last inspection. Ran great.
Seemed to work well for me. Just my two cents.

Despite your experience, hiccups at idle are not normal on a TDI. In fact, they're sometimes an indicator of a worn camshaft. Mobil 1 is a brand name that fits so many of their products that it's not very descriptive. But since you already own the car I'd suggest you switch to a 5w40 oil that meets VW's 505.01 specification. Inspecting the cam for wear is also a good idea, although I suspect it might be fine.

The hiccup at idle could be a worn cam, clogged fuel filter, failed lift pump, failing tandem pump, injector harness issue...lots of possible causes. See if the car shows any fault codes. That would be a good place to start.

Hi all,

Thanks for the replies and suggestions. I suppose I should tell you what I have done to the car since buying it, and what I have discovered.

Oil and filter change
Fuel filter change
Air filter change
Alternator pulley change

And some other minor things..

Also discovered during the fuel filter change that the lift pump had indeed failed, and I have ordered a Pierburg 7.28303.60.0 Fuel Pump to replace the broken one.
Honestly the hiccup is so intermittent it's almost a non-issue, but I will see if the condition improves once the lift pump has been replaced.
As far as codes go, I have a simple OBD2 scanner and it shows no active or pending codes.

I'm honestly putting off the camshaft inspection because I don't want to risk introducing an oil leak to an engine that doesn't have any. I can't hear any abnormal noises coming from the engine, it doesn't stumble on acceleration, doesn't dip below idle speeds upon clutch-in, or anything abnormal. It really does run great. I'm thinking at the very least, I will call the shop that did the oil changes and ask them specifically which oil they used, maybe it will offer me peace of mind.. or perhaps the opposite.

It’s the reason I tried to buy something with low mileage, mines a 2014 that only had 14k on the odometer and the line oil change from the Carfax report was done at Sears, they probably filled it with Dino

CheapBastard said:

It’s the reason I tried to buy something with low mileage, mines a 2014 that only had 14k on the odometer and the line oil change from the Carfax report was done at Sears, they probably filled it with Dino

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Good choice for you. The OP has a much older PD TDI.