P38A 2.5 DSE Ticking noise from engine

As I am currently fighting with a clutch hydraulics issue which has happened since a long lay up of my P38 and then fitting a new clutch, flywheel and then clutch slave, followed by much head scratching on another thread, my mind has wandered back to when I was last using it, and another issue I had in the back of my mind for a to-do list.

Since owning the car, there has been a ticking noise from the engine.

When in the car and driving with slight throttle I used to notice a tap tap tap noise, which roughly correlated to once for every two revs of the engine. As a non Range Rover mechanic, but as a mechanic of another marque I would describe the noise as "cammy" or a worn camshaft lobe.

In particular, the noise sounds just like an old ford pinto engine, such as a 2.0 Cortina, Capri or Sierra that back in the late 80's I would have owned or had friends who owned, and had to fix with a new cam.

Now with my P38, I would jump to the conclusion that it is the same thing, only comes on more loudly when the car is under slight load, seems to go away at higher revs... However, not being experienced with the P38 BMW 2.5 engine, I am a bit more reluctant to just dive in and throw a cam kit at it...

This might be a bit better explained when I mention that a few years ago I owned a BMW 325 TDS e36 with exactly the same symptoms, which I decided to completely remove the head, have it rebuilt and put a new cam into it, with lifters...

With the BMW when I inspected the old cam, I noticed no flats to any of the lobes as you would expect with other cars I have worked on with worn cams, and none of the cam followers seemed either seized or unable to hold pressure when primed in oil.

What's more, with the BMW it cured the noise, but only for about 10,000 miles, when it slowly started to have a quieter version of the same issue and I sold it on!

It's not a loud noise by any means, it could even be something you all experience and ignore, I could be just being picky, but I would really be interested if any other P38 2.5 DSE owners have experienced the same noise.

Part of me even wonders if the noise was only cured for a while on the BMW because I re-timed the cam and diesel pump timing perhaps and it was something caused by wear in the chain etc, which then because it was already worn, rapidly wore further still and caused the return of the noise.. Odd though..

Anyone have any input on this??

Assuming it's not a pully or owt on the alternater belt

Look for soot around the exhaust manifold gasket.

I had a loud ish tick on my old one just after giving it a bootful from the cabin it sounded possible to be chain or top or bottom end

It was the exhaust manifold gasket.

When it's cold just started you can be brace and feel with your fingers.

If it's hot hold your hands very close but not touching and you will feel it

It's possible that's the only noise 1 of both of mine (diesels) have made out the ordinary

Even if it's not it dosent cost anything to see

I will check that out when it is next running.
It would also tally up with my experience with the BMW as the head was removed and overhauled when we changed the cam and followers, so would have had a new exhaust manifold gasket.

injectors seals maybe?

I don't think anyone on here has had to replace a cam on a diesel yet. V8s chew through them but the BMW ones seem solid. Unless something has blocked oil getting up there. Definitely @wammers territory if the nurse will let him out to play.

Worn follower or hydraulic lifter ,what kind o miles has it done ,is service history up to date,piston rings tick if broken,piston slaps another when cold , small ends nip up when over rev"d...put a long screwdriver on your ear ,put the other end on rocker cover ,see were it gets loudest.oh and exhaust manifolds can crack....

I know on VW vans or the Mercedes versions, the vacuum pumps wear and tick tick tick until you pump the brake pedal and it disappears.

Is that a possibility or do they have the same set up as the petrol versions?

Doo said:

I know on VW vans or the Mercedes versions, the vacuum pumps wear and tick tick tick until you pump the brake pedal and it disappears.

Is that a possibility or do they have the same set up as the petrol versions?

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Our 2.5s (early cast inlet I know of my own) dont have a vacum pump for the brakes same as the petrols electronic booster
On my 325tds donor car they do have a vac pump on the front of the cam

stustrong said:

Our 2.5s (early cast inlet I know of my own) dont have a vacum pump for the brakes same as the petrols electronic booster
On my 325tds donor car they do have a vac pump on the front of the cam

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P38s don't have vacuum assisted brakes, the vac pump on the M51 is for EGR operation. The vac pump on the petrols is for cruise control.

wammers said:

P38s don't have vacuum assisted brakes, the vac pump on the M51 is for EGR operation. The vac pump on the petrols is for cruise control.

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I knew the petrols didn't have vac assisted brakes. But I wondered if the diesel may have been different.

Which reminds me, I'm off to have a squint at my cruise bits....

Doo said:

I knew the petrols didn't have vac assisted brakes. But I wondered if the diesel may have been different.

Which reminds me, I'm off to have a squint at my cruise bits....

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One of the great things about the P38 is how similar (and interchangeable) all the bits are. There are a few big differences between models: the engine, obviously. Because the engine the gearboxes are slightly different for the 4.6. Later models the traction control and because that was different the diff are slightly different. Then there's a the low spec and higher spec cars which require different BECMs and I think the alternators are different for later cars too. The diesel lump was a tricky shape so it lost the front harmonic damper. Other than that it is pretty much cosmetic, like twin pipes after the mini-facelift in '97.

When did TC become standard fit? Think mine has it... Why would a 4x4 like the RR need TC? Unless it's for those damn foo's with no ability

Doo said:

When did TC become standard fit? Think mine has it... Why would a 4x4 like the RR need TC? Unless it's for those damn foo's with no ability

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Rear was option up till 1998. Around then 4 wheel TC came as standard. It is clever, a bit too clever. It locks the brake on the spinning tyre to sen power to the non-spinning tyre. Try getting stuck without it! Problem is, braking on the wheel slows you down. It helps a bit but with the 2 wheel version if a front wheel starts spinning then that tends to take all the power. 4 wheel version is much better but still no competition for a locking diff.

Grrrrrr said:

One of the great things about the P38 is how similar (and interchangeable) all the bits are. There are a few big differences between models: the engine, obviously. Because the engine the gearboxes are slightly different for the 4.6. Later models the traction control and because that was different the diff are slightly different. Then there's a the low spec and higher spec cars which require different BECMs and I think the alternators are different for later cars too. The diesel lump was a tricky shape so it lost the front harmonic damper. Other than that it is pretty much cosmetic, like twin pipes after the mini-facelift in '97.

Click to expand...

Front harmonic balance from the axle that is.

wammers said:

Front harmonic balance from the axle that is.

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Yes!

Washed her a reward as just returned from Scotland didn't miss a beat.