Diesel died...how much oil should sit in rocker?

[jamiehamy]

Hi all,

Dumpy Todd the 1.7d died on the dual carriageway today with buzzer of doom and light. Taken home by AA and she starts again, but runs rough, but on all 4 cylinders according to AA man. Sounds quite clattery, more so than normal (he always ran very nicely).

AA man and Peter at Wagonbuild have suggested dropped valve, or tappets. I took the rocker cover off and the engine is immaculate, but I noticed a distinct lack of oil up there.

How much should generally sit there once the engine of off? There is none sitting in the bottom like I expected. I'm wondering if oil is not getting up there (a new oil pump was fitted about 6 months ago).

Also, the oil filler is leaking oil, which suggests it's pressurising somehow - any thoughts?

We're supposed to be going to Tiree next week and this has scuppered the plans. If all else fails, it's a new engine but would rather try salvage the trip.

Would be great to hear thoughts,

Thanks, Jamie

[HarryMann]

Well Jamie, taking just the rocker cover off can hardly tell you the engine is 'immaculate'... of course it's clean in there if oil changed regularly. Shouldn't be a lot ad it drains back down.
And then why did it need an oil pump, not that usual to change on a diesel or anything these days, up to 2 or even 3 00, 000 miles.

No you need to get a standalone mechanical gauge plugged in and check the oil pressure properly, cold then hot at 900 and 2000 revs... just to start with.
If below spec. then probably mains or ends. Does it have a bottom end rattle undrt load as opposed to a diesel rattle at idle.

[jamiehamy]

hmm. Oil pump was done as a preventative measure as it has 170k on original engine. There is no bottom end rattle I can hear, but tbh, i don't want to run it under load until i know the issue. It will eventually settle to a rough idle, there is smoke, greyish!black, but that clears.

In terms of the rocker, you may be right, but i've seen plenty well maintained engines that are still gunky and with yellow staining. I know it doesn't count for everything, but it's been a cracking engine and never caused any borher before, bar the buzzer of doom last year which fixed itself and went off with a ligt tap of the dash!

where is the best place to take the pressure - presumably at the end of the head?

Thanks, J.

[jamiehamy]

Looks like I've managed to fix it.

Took the sump off and the oil pump, just in case i'd fitted it wrongly (!) or it was broken. The pump 'looked' fine, although when I compared it to the old one, it was clearly more poorly manufactured - ragged edges, some parts different sizes on so on. Anyway, I swapped the old one back in and put everything back on, filled with oil and when I started, the same again. It idled this time, so I had a look at the engine when running and could hear a noise from the back - and found the oil pump drive was loose! It was sitting proud and the bolt for the bracket was loose. Checked the location of the oil shaft, refitted, tightened, and now running fine.

I did noticed that the tappets had wear marked where the cam was hitting it. On my Corrado I believe the tappets are designed to rotate and wear evenly. Is this the case with the t25 diesel? If so, I'll replace them.

Happy he's running again and hopefully our trip is back on. Such a simple thing, and the AA man never noticed when he told me it was internal damage, nothing external was the problem.

Fingers crossed!

[HarryMann]

You mean the vacuum pump was not engaged properly into the intermediate shaft... removing drive to the pump

[jamiehamy]

That'll be the one harry! I wasn't driving at the time it failed, so didn't get a chance to notice if the brakes went t the same time.

I've encountered another issue unfortunately - the engine is pushing oil out of the oil filler cap. I loosened it when running and the oil started pouring out.

I disconnected the breather pipe on the rocker cover and a whoosh of air escaped and continued fairly strongly. The pressure at the oil cap disappeared.

I've read up and sounds like low compression, which I can't test just now. could it be anything else? It's always been perky enough, never used oil and no smoke.
Thanks, Jamie

[HarryMann]

Blocked breather somewhere, otherwise worn or broken rings.
Oil level spot om?

[jamiehamy]

oil level is spot on. I've got her driving with a temporary 'catch tank'. Engine is fine, except there is a clacking noise. Judging by the frequency, it's from only one of the cylinders. I'm taking the tappets out tonight to check if one is seized or damaged. I'd have ordered new ones but doesn't seem like they are readily available.

Starts just the way it did before the problem, drives fine and no visible smoke, and no misfiring. Just need to sort the clack and backpressure - i'm guessing they are related. Looking like an internal problem now, but i don't have a diesel compression tester, which is a real pain.

[HarryMann]

Have you managed to loan a mechanical oil gauge snd check the pressures?

[jamiehamy]

Not yet harry. A friend has one but it's for petrol. The rocker pressure has subsided and it's back to normal on that front, it just sounds like an old transit.

Strangely, the clacking is not there when it's cold, it takes about 45seconds for it to start and get louder. It's only just audible in the cabin. I took the rocker, cam and followers out and all look in good condition, little visible wear and no scoring.

*sigh.

[HarryMann]

I meant oil pressure off the filter housing port.
They can definitely drive you loopy with these ticks, rattles and knocks... @@