Thread: D1 V8 top end rattle. Ideas?

Thanks Bee Utey, I'm pretty sure that the sump is still going to be clean inside, as when I rebuilt the motor (or finished it at least) 13 months ago, it was spotless inside afterwards. It's covered less than 10k kms since with 2 oil changes.

The only thing that rings slight alarm bells in the back of my mind is that I used the old black silicon stuff to seal the sump, and i have heard stories of the excess breaking off and clogging the oil pick up, so I'll definitely drop the sump and take a look.

The reason that my neighbour's diagnosis of cam bearings rang true with me was that it was one of the only few things that I didn't change during my rebuild.

I wonder if there could be an issue with the oil pump? The noise could be put down to oil starvation at higher revs?

Originally Posted by Presto

I wonder if there could be an issue with the oil pump? The noise could be put down to oil starvation at higher revs?

That was something else I was nervous about, as I didn't change it. The oil pump is the crank driven one in the front cover, and I did dismantle, clean and measure it when the engine was in bits last. It was within spec at the time, but given that I would like the D1 to last a fair bit longer, and for the sake of 75 pounds, I'll look at changing it I think.

Well 11 months on from the post above, and I did little to (or in!) the D1 except give it an oil change after it had sat still for 6 months.

I changed the thickened Castrol GTX 20/50 for Shell Helix HX7 (10/40), and gave it a run for about 150km over 2 days. All seemed good, apart from the sound of crickets from the engine under acceleration. Stuck lifter, I thought.

So I had a hunt around and found Liqui-Moly. Paid my $15 and bunged it in the crankcase. Allowed it to idle for a few minutes while I closed the garage doors, and then took it for a short drive. Noise gone! Woohoo! Following day, was heading off on what was supposed to be a fairly long trip (and enjoying the new quiet D1) - as soon as it was up to full operating temp about 6km later, the oil light came on. A few choice words, and a swerve for the side of the road, and hit the kill switch.
Gave it 10 mins, and restarted, no oil light, so headed for home. Had to do the stop, switch off, cool down, restart trick twice more before getting home.

Thinking the new oil and Liqui Moly weren't playing nicely together, I went out and replaced the oil and filter with new (after only ~160km!).

Still no different. Oil light goes off straight away when cold, or even starting from warm, but at full operating temp, the oil light comes on.

I've pulled the oil pressure relief valve, and that was clean and moving fine.
Next job tomorrow is to hook up an oil pressure guage to get a proper reading.

Any ideas beyond that?

Change the oil pressure switch?

Originally Posted by bee utey

Change the oil pressure switch?

Tried to find one today. 4 places didn't have one, and can't get me one until mid Jan. Everyone seems to have closed up for Christmas today

I'll stick a Wanted ad in, see if anyone has a spare.

I have a couple of ideas/possibilities

For oil problem i would go with oil sensor maybe buy a sanwich plate and a mechanical oil preassure gauge or good quality electric one and cheack what the preasure is doing.

If oil preasure is good i reckon the knocking noise is it is predetonating causing a loud rattle sound or knocking

My reasons for this are:
only under load
after change of cam
pump on way out causing runnig lean

BUT Does the warning light come on after a above 4k spin on the tacho? I was thinking for them all to be related, it maybe big ends.
Did you do a bearing crush reading during the rebuild with plastigauge?

what about oil preasure bypass stuck but you would have to be unlucky?

Originally Posted by Tdi Nico

I have a couple of ideas/possibilities

For oil problem i would go with oil sensor maybe buy a sanwich plate and a mechanical oil preassure gauge or good quality electric one and cheack what the preasure is doing.

If oil preasure is good i reckon the knocking noise is it is predetonating causing a loud rattle sound or knocking

My reasons for this are:
only under load
after change of cam
pump on way out causing runnig lean

BUT Does the warning light come on after a above 4k spin on the tacho? I was thinking for them all to be related, it maybe big ends.
Did you do a bearing crush reading during the rebuild with plastigauge?

what about oil preasure bypass stuck but you would have to be unlucky?

Nico, yes I did the Plastiguage test, so am confident that big ends are ok (the old ones showed some standard light, even wear, nothing excessive. I changed them because I changed the rings).

The fuel pump was changed, along with the injectors (put some Bosch Gen III in), and have rechecked timing, and all ignition components. It has LR rotor button and dissy cap, with Bosch coil and NGK spark leads - all known good. Vacuum advance tested and good also.
So I'm reasonably confident that it's not predetonation, particularly as it disappeared almost instantly with adding the LiquiMoly.

The only thing I'm not confident on having done right during the rebuild is the rocker pre-load (never had to do that before), which if logic serves me right, could lead to excessive cam/lifter wear if not correct?

Still got to source a new oil pressure switch. Tried 3 more places yesterday with no luck, when I have one of them I'll try the test with the pressure guage.