L322 Paper test for Diesel in engine oil

Hmm so the oil in the wife's BMW has been in longer but the car is considerably lower mileage. Results are very different from mine, maybe an oil change is the best course of action considering it's so cheap. I'll do it myself and get a good discount on parts so it'll only cost around £30

Certainly the two results are poles apart.

I checked a couple of diesel cars at work today and they were all similar to the BMW.
Defo going to change the oil.
The thing is, I went for 10-40 because it was suggested it may quieten down the noisy tappy engine but it didn't. I'm tempted to try 5-30 to see if that makes it better or worse.
Problem is I'm of to the Lemans 24 hour on Wednesday in the rangie. Don't want to screw it up more than it already is

Forgive my asking, you've recently had your injectors overhauled,
Is the oil older than that job?

No they were used but tested good,
And yes that may seem like a waste of money but the symptoms were close to gearbox issues, now I know the gearbox is ok I'm happy to throw a few hours and £'s at other issues. Engine runs great but is tappy mainly at 1500 or more revs, more of a rattle than a tap

The current engine oil, does it pre-date the fitment of the 'used' injectors?

Yes, that's why I'm changing it. It was suggested to me that the old injectors may have been leaking fuel into the oil. I don't think it will fix the noisey engine though as I did an oil change fairly recently and the noise didn't change, it has got louder lately though

Could it just be that the "new" injectors are tappy?
I know some early injectors made a distinct clicking/tapping noise.

Hence me asking, I was curious as to whether the oil you still have was in with the old injectors.
You've got to drain it out based on the evidence supplied.

As to the tappets, maybe they are worn or full of the less viscous diluted oil you currently have in.
See how it fares with new oil, it may quieten things.

Le Mans...nice one, just watch out for aerobatical Mercs

Unlikely as the engine noise hasn't changed since the injector change, it had got more tappy before I swapped them

Yeah I agree , got to be the next step. It can't do any harm that's for sure, although I'm still unsure on wether to go 10-40 or 5-30

I think I use 10-40 in mine. In an older engine I always tend towards thicker oil than thinner.
Mine has a bit of a noise at idle when warm that sounds a bit like piston slap but it's not changed in 12k miles so I've kinda given up worrying about it!

I probably should ignore the noise mine makes. I've heard plenty that sound worse, just don't want to waste money replacing the engine if it's just a case of changing to the correct oil

So oil change completed today, decided to do a flush with Wynns engine flush followed by new filter and 5-40 fully synthetic oil
The engine was quiet, no tapping top end,
Well for about 5 miles, the. It came back,
I'm wondering if I should be using something like 5-30
Might try one of the top end restorer additives
At least it's not cam chain noise

I use helix 10w40 in mine.

Last time I changed the oil it was for a 10/40 oil and that made no difference at all.
Maybe it was the flush that helped this time

youmitegetian said:

Last time I changed the oil it was for a 10/40 oil and that made no difference at all.
Maybe it was the flush that helped this time

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Be careful with those flushes. They can get rid of all sorts of crud that is helping to seal parts. Better to do more frequent oil changes for a bit. Check handbook for what grades your engine will take. I'd have thought thicker oil might quieten her down unless a passageway is blocked somewhere. How about the oil pressure relief valve? Is that sticking?

Yeah I was a little worried but had heard doing a flush can be ok if the car has had a good history of regular servicing which this one has,
I wasn't aware there is an oil pressure release valve. Where is it?

youmitegetian said:

Yeah I was a little worried but had heard doing a flush can be ok if the car has had a good history of regular servicing which this one has,
I wasn't aware there is an oil pressure release valve. Where is it?

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Not sure on the L322 but I'd imagine it must have one?! @Saint.V8 will have had it out if it has one.

youmitegetian said:

Yeah I was a little worried but had heard doing a flush can be ok if the car has had a good history of regular servicing which this one has,
I wasn't aware there is an oil pressure release valve. Where is it?

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Every engine has an oil pressure relief valve. If they didn't, when the oil was cold, the system would hydraulic up.