Leakdown Test Kit

[Jocklandjohn]

I'm trying to find a reasonably priced leakdown kit with the twin gauge set up. As far as I can see all the sub £50 kits are only for petrol engines. However they all (diesel or petrol) go to 100psi/7Bar so does that mean that the only difference in usage is the fitting for connection to injector/glow plugs on a diesel versus spark plug sized fittings for petrol?

The expensive Laser Cylinder Leakage kit notes it has petrol fittings, but has the adaptor for diesel testing (Quote: "As Supplied in Compression Test Kit Part no 4510) which suggests that it is possible. But I'll need an adult to confirm! I have a compression test kit (with both injector and glowplug fittings) so can I assume its possible to simply use a petrol gauge on them?

Alternatively a pointer to any modestly priced diesel tester would be welcomed.

[hurbie]

can't comment on this , but if i remember well , you did a compression test with some decent outcome (all cylinders more or less the same value. so i don't think you gain anything from your leaktest .....

to me the problem isn't compresion or leaking valve's , but more fuel/air related...

[Jocklandjohn]

Yes I did the compression test, but from reading various bits of info was under the impression that a leakdown test might be a useful thing to do as well, and if the kit wasn't expensive might be worth it. But if someone experienced is advising its a bit of a waste of time (given my good compression test result) I'll gladly defer to your experience! Thanks!

[jason110]

If your compression test is good. You’re wasting your money on further testing 

compression test proves integrity of the valves and valve seats and the piston rings. 
 

if you’re still having issues it’s fuel / air / combustion related. 

[Jocklandjohn]

Thanks - I wasn't sure about any of this stuff - its all new territory for me. The compression test seemed to tick all the boxes for a sound engine (from what I've read about such tests and what they indicate). My only additional thought was whether the leakdown test would allow pinpointing of specific pressure loss areas in the system which might account for my (apparent) lack of air in the combustion sequence despite everything *seeming* to be otherwise ok.

I'm taking the radiator out shortly for a recore, so will pull the intercooler out for a flush and remove and check carefully all the piping from the air intake(s) (I have two) to the engine to ensure all the hoses are intact. If thats all ok, then I have the recently overhauled FIP to install and will also do a timing belt change as well and make sure all the engine timing is spot on.

[hurbie]

can you post some pic's of your engine bay , and the air intake's ?

[Jocklandjohn]

Aye sure. Fairly straightforwards. Additional hose to the right of the air filter box beside the window washer bottle is a second air intake from the top side of the front wing which joins a Y just at the pipe with red tape on it coming from the Eberspacher (I fitted that to try to resolve the running issues by getting more air in - main air intake is a Safari snorkel).

Engine is a 200Tdi fitted in place of the original 2.5TD (19J). Been in there for over 20 years, oil and filter changes every 4K miles, fuel filters regularly, valves checked regularly, air filters replaced too.

 

[muddy]

Air filter is too restrictive, take the pipe off the turbo intake and take it for a quick run making sure there's no debris in the engine bay before you start.

[Jocklandjohn]

Before the recent turbo replacement I tried that at the suggestion of a local LR mechanic expert who did it as a favour for me (with a slip on K&N element clamped on the turbo housing) and it made no difference - he gave it a visual once-over and had a general poke at various bits and thought nothing seemed obviously wrong, and then took it for a hard run but agreed the performance under load was carp. Conclusion then was it's pointing to the FIP and/or timing issue (hence I've had my spare old pump overhauled last week, and a timing belt change to get done asap.)

He then let me drive his - exactly same - 110, 200Tdi, 1.2 gearing, deeper intercooler and modest tweak of pump, and his was massively different, pulling up hills easily, no smoke and with lots of low-end grunt. I've driven several other 110's in HT and CSW forms over the years for work, some heavily loaded and all pulled like a train and mine by comparison is utterly feeble on a slope.

When you say "too restrictive" do you mean that the filters/housing for the 19J engines were less 'airy' than the later 200/300Tdi ones? As in - fitting a larger filter housing/element would be an improvment?

Edited July 31, 2023 by Jocklandjohn

[Jocklandjohn]

UPDATE

Progress! After literally YEARS of chasing this issue of desperately poor running and replacing lift pumps, fuel lines, injector nozzles and more, I believe I have found the culprit.

I replaced the thin boost pipe from turbo to FIP and whilst at it decided to check over all the high pressure hoses in the turbo-to-intercooler-to-manifold line. All were intact, as they have been every other time I checked them. I put them all back on and added extra jubilee clamps on all the silicone/alloy joints and went for a run. It was performing worse than it had been before I touched it! Literally - so much worse it was hard to believe. I was getting high EGT's and lots of smoke, couldn't rev much over 2000 rpm and generally just rubbish.

Back to the piping - obviously something amiss there. All 'soft' pipes intact and properly connected. So...to the alloy pipes. One of them has a small angle in it created by a cut/weld to give a slight direction change - it was fitted decades ago when I had an Allard intercooler fitted to the 2.5TD. With a cursory glance it looked fine, but I could see a slight black discolouration on its back side where its normally hidden from view. It looked ok but I gave it a pull and the joint opened!

Now, because my 110 was originally a 2.5TD it has the air filter box vertical in the front engine bay passenger side with a support leg in the way of the lower intercooler inlet which means the piping has to be forced around various bends to get to the turbo outlet. What seems to be happening is that the alloy *looks* ok but when all the piping is shoved together its under a degree of tension and only needs the pressure build up when the turbo does its thing to allow the pressurised air to escape. Because I took it apart and reassembled with extra clamps I must have put more pressure on the alloy section causing the joint to be more open and performance to worsen after I fiddled with it.

I gave the joint a clean, splodged some weld on it and put it back together and went for a run.

Oh my! I now have very little smoke, it revs like a champion - I can now get over 2000rpm! The ooomph in every gear is astonishing and EGT's are so low I'm having trouble believing the gauge is accurate. Uphill running in 3rd is effortless and I can even accelerate! The smoothness of the engine is also noticeable and running temperature is much lower.

After SO long chasing an issue that was really getting me exasperated it turned out to be something simple, but 'hidden'.

Edited August 28, 2023 by Jocklandjohn

[fmmv]

Well first thanks for letting us know, and well done for finally running it to ground. The joys of boost!

I had a similar thing once, I had a Alisport intercooler (300tdi)  and it was connected to the inlet manifold by an alloy pipe, the joints were by very short straight silicon pieces. The problem I had was that the engine rocked forward on its mounts enough to push the intercooler forward as there was very little 'give' in the pipes; that in turn made a slit  in the intercooler where the mounting boss had been welded on. The fix was weld, but I replaced one of the hoses with a 'hump' hose, which lets the engine move a little without pushing on the intercooler. These things are often very hard to spot.

[Jocklandjohn]

54 minutes ago, fmmv said:

Well first thanks for letting us know, and well done for finally running it to ground. The joys of boost!

I had a similar thing once, I had a Alisport intercooler (300tdi)  and it was connected to the inlet manifold by an alloy pipe, the joints were by very short straight silicon pieces. The problem I had was that the engine rocked forward on its mounts enough to push the intercooler forward as there was very little 'give' in the pipes; that in turn made a slit  in the intercooler where the mounting boss had been welded on. The fix was weld, but I replaced one of the hoses with a 'hump' hose, which lets the engine move a little without pushing on the intercooler. These things are often very hard to spot.

Its quite astonishing that something so small (apparently) can have such a big effect. It was the last thing I'd have expected to be the cause!