Hi had a pressure test on a newly aquired L200 52 plate and the results are a bit baffling..

2 cylinders were just below minimum and the other 2 were just ABOVE maximum !!

If...the test has been done correct what would that point towards ??

Its not unusual to have different compression reading in different cylinders, I was always told that as long as they were within 10% of each other it was normal, radical differences could point to head gasket failure or piston ring failure, or valves worn not seating correctly.

Squirt a bit of engine oil down the bores and repeat the test if it gives a more even result then the rings are worn.

Yeah,what GB said.You'll probably find its nothing to worry about...

Head gasket i can cope with but not sure about changing rings !

What is the issue that's caused you to get a compression test? What is the mileage?
If its just a little wear on the rings then its just a sign if engine wear, is there any indication of slightly blue-ish smoke when its running?
you could change the oil to a slightly heavier viscosity which might help a bit.

The truck is very reluctant to start and the mileage is 125,000, so lots !

It has had a hard life and i got it to see if i could revive it and give it another hard life ...

The EGR has not been done on it so it has 125,000 mile of gunk floating around in it and has pretty much been neglected since new. There is oil in places there shouldn't be, the turbo wasn,t working and when you got to about 2000 rpm there was a cloud of whitish blue smoke appeared behind you and power was sucked from it along with an EML

There is a big dent in the oil cooler and the timing belt was hanging on by a thread, the balance belt had snapped for ever ago and was floating around in the case...( amazingly the timing was still correct,no jumped teeth )

I took it straight to a garage to see what else it needed for an MOT expecting a massive list................................. a CV boot !!

So there we are it doesnt start runs like crap and it passed an MOT


so far i have done...

new belts and tensioners

new oil cooler
new oil filter
new air filter
new fuel filter
took egr off
took inlet manifold off and took about a pound off crud out of it
put new turbo actuator on (as noticed while in there the other one had been hit by something and couldnt activate)


because of the mileage and crud in the engine low compression etc i plan to take the head off and try and see what is going on.

i am not a mechanic by any stretch of the imagination but i am determined to give it a go

Where do i start ?

could this be a fuel pump problem causing this perhaps ? @Alan G is our fuel pump champion on here and may be able to advise you on that one.

The fuel pump on a diesel is one of those things that i look at the same way i would look at an alien if it was sitting in my garden........................... Very confused and a bit scared.

I like you already Bart..i too Believe in aliens..dont be scared mate,they are usually friendly..

Daz

A fuel pump won't give low compression in the cylinder, sqiurt some oil down the injector holes and do the compression test again and see what the results are, if the are the same then its hopefully just a head gasket issue and its time to get the head off and get it pressure tested and the valves recut etc

Given its hard life and lack if servicing its likely that the engine might be pretty worn, but to what extent are you going to go with a rough truck, if your doing the head and the rings then your effectively doing a full rebuild and taking the engine out... Is it worth going to that extent or just moving it on and spending the money on a better truck?

What year is the truck as after 2001 they had fly by wire engine control on them while older ones just use cable throttle. If it's a later one is it possible the crank position sensor could be damaged and giving a duff signal that won't help starting iirc.

Quote: robl200 wrote in post #11

---

What year is the truck as after 2001 they had fly by wire engine control on them while older ones just use cable throttle. If it's a later one is it possible the crank position sensor could be damaged and giving a duff signal that won't help starting iirc.

---

Quote: bart wrote in post #4

---

Head gasket i can cope with but not sure about changing rings !

---

These engines are pretty straight forward to work on. I'm no mechanic either but re built mine a while back

Would be worth checking the valve clearance

Crank posistion sensor is a good one to check as mine failed and it took the MITZI garage over a week to diagnose and ended up £600 lighter

Quote: bluesj wrote in post #15

---

Would be worth checking the valve clearance

---

Everything stripped off from the head and ready to take off, apart from injectors (aint got an injector socket )

So i need to go get a socket, and what size is the head bolt fitting ?

and a torque wrench might come in handy i suppose........

My head bolts on my 4m40 engine where 14mm and where the spikey type head if that makes sense. Not the hex head. Not sure if they are the same as your engine tho. Torque wrench and angle gauge needed. And a tap set to clean the threads out on the block.

Do you mean torx fittings?

Daz

Yes. Those are the ones. Thank you daz. I couldn't remember the name and spikey head bolts was the closest thing to a description of them that I could come up with.

They are called TORX