Thread: How to compression test a 300tdi

before you start.

buy the RAVE CD. you're going to need it to tackel the head.

before you pull the head with the thrmostat off and the cooling sytstem drinedput some glad wrap over the thermostat hole and crank the engine over with all the glow plugs in but the fuel pump disabled if it huffs the plastic then youve likely done the gasket.

to check TDC..

theres mark on the harmonic blancer and a mark on the timing case, if you want it really accurate therees a slot in the flywheel that lines up with the center of the bell housing drain but if youve got the rocker cover off you can get near enough for most purposes by watching the valves, as the exhaust valve closes on one cylinder watch for the inlet to open ,when the valves re in the middle of the overlap you're just past TDC. take the cylinder number that is rocking away from 5 and that number is the number of the cylinder that is TDC post injection.

Injection occurs on that cylinder at around the time theinlet valve on its partner cylinder begins to open.

Originally Posted by Blknight.aus

to check TDC..



........................... as the exhaust valve closes on one cylinder watch for the inlet to open ,when the valves re in the middle of the overlap you're just past TDC. take the cylinder number that is rocking away from 5 and that number is the number of the cylinder that is TDC post injection.

Injection occurs on that cylinder at around the time theinlet valve on its partner cylinder begins to open.

Very clever and thanks Dave , I'm never too old to learn. Simplifying your statement a little bit I come up with this.

............................. as the exhaust valve closes on any cylinder watch for its inlet valve to open, when the valves are in the middle of this overlap period you're just past TDC (on the inlet stroke). Take this cylinder number away from 5 and that number is the number of the cylinder that is at TDC post injection (on the ignition stroke).

So if this is on cylinder no.4 you're at TDC on no.1.


Makes sense and thanks again.


Deano

Originally Posted by DeanoH

Very clever and thanks Dave , I'm never too old to learn. Simplifying your statement a little bit I come up with this.

............................. as the exhaust valve closes on any cylinder watch for its inlet valve to open, when the valves are in the middle of this overlap period you're just past TDC (on the inlet stroke). Take this cylinder number away from 5 and that number is the number of the cylinder that is at TDC post injection (on the ignition stroke).

So if this is on cylinder no.4 you're at TDC on no.1.


Makes sense and thanks again.


Deano

Near enough.

its referred to as the rule of 5 the other one you need for the tdi is the rule of 9 which is the same thing done for the valves,

Ignition is not a stroke it is an action post injection and you're on the power stroke (induction, compression, combustion/power, exhaust, or suck, squeeze bang, blow.)

when you do your valve adjustments (assuming they are already within bold adjustment) there are 2 common methods and a couple of variations of each,

the most common method is to set TDC and then adjust all loose valve rockers, roll the engine over 360 on the crank so the companion piston is on TDC then adjust all the other valves (and this works on all landrover 4 cyl engines)

the other method is to set any valve to fully open and then adjust its companion valve (9-open=companion)

Blknight.aus. Hi Dave.

I have been working on the beast today and didnt see your message untill I nearly have the head off. It will be off tomorrow. I am a bit slow nowadays (comes with age I think). I have noted all your comments and they will help me greatly. Like I said in a previous post, I am not new to tinkering with cars, but I am certainly no mechanic. Thank you very much for your help and should I be in trouble as I progress through this problem I have no doubt I will need some assistance to get the Beast done and on the road again. Have a beaut day Dave - Gerry (wedgetail37)

Hi Deano.
I am trying to grasp what you are saying and I am sure I will understand as I progress through the job. I am at the stage that after removing the Head Bolts I will be able to lift the head and inspect. I have to lift it off attached to the intercooler and the turbo as I could not get the second long bolt out between the intercooler and the manifold. The first one (closest to the rad) was easy but the second one was already rounded. I am not sure how I am going to fix this problem yet when I get it off, as I want to replace the manifold gasket during this repair. Any ideas?? Its in a difficult position. Other than that I am progressing just fine thanks to you and others on this beaut Forum with so many helpful people. Why do I love Landrovers so much? It must be the legend that Landrover is and the people that own these legends. Anyhow mate, have a good one and thank you again. See ya - Gerry

Hi Gerry, removing the manifolds from the head (in situ) makes the job a lot easier. I've only done it this way. The head's heavy enough and awkward enough without the added weight of the exhaust/turbo.


From memory, for the inlet manifold, remove the heat shield plate at the rear of the manifold (if fitted) being careful not to round off the little 4 mm? bolts that hold it on. They come in from the bottom of the manifold. There's only two or three bolts that hold the manifold on with the front and rear bolts fitting into 'slots' in the manifold. These are the same bolts that hold the heater pipe mountings.


You'll now have access to the exhaust manifold nuts (on studs), a bit fiddly on the nuts to the centre of the manifold. You'll need a longish extension here but the nuts/studs all line up through gaps in/under the exhaust manifold even though this may not appear so at first, you wont need a socket uni joint. I found 3/8" drive sockets a better fit for this job. Some or all of the exhaust studs will come out with the nuts but this is no big deal in fact it makes it easier when pulling the manifold to the side when removing the head.




Deano

Good morning Deano.

" There's only two or three bolts that hold the manifold on with the front and rear bolts fitting into 'slots' in the manifold. These are the same bolts that hold the heater pipe mountings."

Thats the problem above. One of those bolts are already round and I cannot remove the inlet manifold. Thats why I had to disconnect the exhaust flange. It is a real nuisance, but I hope when I get the whole lot out I will be able to somehow remove the bolt.

I have had this problem 3 times , twice it was the head , but once it was just the cap on the expansion tank . probably too late now though . chances are it's the head .