Suspected head gasket

Hi, ive put a disco 200tdi into my defender. Basically on start up the engine wont rev and bellows out white smoke. Its also a little underpowerd which is noticible mainly when pulling away in first untill the turbo kicks in. Also noticed its low on oil (dropped to the min level in 800 miles) also the coolant level is low. Also noticed that wher the bellhousing is there is a little oil leak (always has been) but now it appears that coolant is leaking out of there as well. Is this a head gasket or somthing else? Cheers for any advice! Pete

08mckerp said:

Hi, ive put a disco 200tdi into my defender. Basically on start up the engine wont rev and bellows out white smoke. Its also a little underpowerd which is noticible mainly when pulling away in first untill the turbo kicks in. Also noticed its low on oil (dropped to the min level in 800 miles) also the coolant level is low. Also noticed that wher the bellhousing is there is a little oil leak (always has been) but now it appears that coolant is leaking out of there as well. Is this a head gasket or somthing else? Cheers for any advice! Pete

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I'm supposed to be doing a uni essay but I can't keep off here! It doesn't sound good to me but all signs are pointing towards a blown head gasket or possibly (worse) a crack in your cylinder head or the block. The first thing that I'd be checking is that there are no coolant leaks anywhere externally, especially where the heater matrix pipes connect towards the back of the engine. Even water leaking past your jubilee clips towards the front of the engine will find its way down to the bell housing when travelling.

If you look at the dipstick, does it show any signs of water contaminating the oil or does the oil look very diluted? Usually you'd find that if water is getting into the oil, your oil level will increase but it would depend very much on which part of the head gasket has blown. This is what I find puzzling about your situation. For oil to find its way into the bell housing, it must be getting past the crank rear oil seal and for you to find coolant in there too, your oil level would almost certainly show signs of increasing volume or water dilution.

The best thing to do, as is always the case in these situations, is to have the engine 'leakage tested'. I'd strongly suggest that you do this before you decide to whip the head off (which it sounds like it needs either way) because at least then you will know which cylinder(s) are playing up and you'll know to check those particular cylinders particularly carefully for cracks etc.

A head gasket can blow in quite a few different ways and in most cases, you should be able to get a dead-cert answer with a few simple tests:

1) Start your engine and let it run up to temperature.
2) Remove the breather pipe between the cyclone breather and your air intake - but not the pipe between the cyclone unit and the sump.
3) Press your thumb firmly over the opening of the cyclone unit opening
4) Rev the engine hard for five seconds
5) Quickly release your thumb

Does it throw a smelly oily vapour / oil out at you and hiss? If so, you have a head gasket leak between a cylinder and an oil passage / push rod hole.

Repeat the steps above, but whilst keeping your thumb pressed over the cyclone unit hole, have someone remove the dipstick after five seconds of hard revving - does it hiss? This will also confirm headgasket failure between a cylinder and an oil passage / push rod hole.

6) Replace the breather pipe
7) Place a towel firmly over the top of the header tank cap
8) Remove the cap from your header tank carefully

Does it blow the cap off?

9) With the header tank cap removed, rev the engine

Do you see any bubbles? Does the coolant smell of fumes?

That should get you started!
-Pos

sorry to drag this up again. discovered my apparent coolant leak was coming from the heater pipes so thats stopped that. Did all the tests of covering dipstick etc etc and didnt get any pressure building or anything so decided to hope for the best and just carry on. However its still very underpowerd until the turbo kicks in and wen starting it struggles to rev untill the engine is warm and it kicks out a load of white smoke. If its sat outside over night it will not rev at all for 30-60secs and it just creates a smoke screen of white smoke. It feels like its got water in it could it be i have a small gap in the head gasket thats just letting a bit of water into one or two of the cylinders which is causing the engine to struggle untill it gets up to temp and all the water has been burnt off / forced out? It is also making a loud tapping noise and runs very lumpy when idling but smooths out when you rev it at all. is this likly to just be the tappets? Cheers for any advice

if white smoke dissapates quickly its water vapour ,hangs about unburnt fuel check tappets gap and function push rods can punch through brass followers ,(not allowing enough air into cylinder to create good burn most head gasket failures are as you described gasket appears intact but staining shows a leak

kicks out white smoke until its warmed up a bit. initially it smells of diesel but only right at the start, which i guess is just a bit of unburnt fuel as its not warm enuff for 100% combustion. worth taking head off to have a look?

over fuelling has the IP been tampered with??

redhand said:

over fuelling has the IP been tampered with??

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nope. and it doesnt rev for way after the smell of diesel has gone. its exactly like if u splash a bit of water into the air intake if u go thru a ford or sumthin to fast. just loads of white smoke and wont rev.

Sounds like the timing is out. Did you replace the timing belt when you swapped engines?

yup. its bin fine for a year. Thers no smoke and it runs smoothly when warm. just underpowerd.

the diesel smell on start up last a second or 2 but the smoke contines for 30-60secs

sounds like timing to me ,mine was a tooth out and i used to get lots of white, but now just a slugg of black on start up ;-)

Sounds like pump timing. maybe jumped a tooth if it was ok previous.
Good hunting

you guys rekon its timing even tho smoke clears and runs fine wen its warm?? id love to think it was that! doesnt smoke when driving or anything. im just concerned that the white smoke is distincly like water vapour as the smell clears. its quite hard to explain its reving issue when cold. will have an investigate and let you guys no.

Just now it might be summit to do with the weather. If after ye've run yer motor fur a bit and then parked it up, it'll cool down a lot quicker and possibly cause condensation givin' ye the white smoke.... just a thought

pulled it all apart. Head gasket leaking between cylinder 2&3. also pistons are hitting a couple of the valves. Could this be a warped head?

cam timing if valves have been touching pistons

yer, think whats happened is that the timing belt has broken at sum point and the pistons have then hit the valves, as the ones that are opposite the marks on the pistons appear newer and undamaged. very little sign of leak on the gasket though a large stain on the head between the 2 cylinders. is this common or does it indicate a warped head? or is it possible that the head was incorrectly refitted if the valves had been replaced?

For the small cost involved, have the head skimmed and checked for leaks if at all possible.

Regards

Phil*

if the valves hit the pistons on a 200tdi then they will bend the pushrods, as they are the weak link if you like. So check all of the pushrods and make sure they are all ok, they're only a couple of quid each. If you have a slightly bent pushrod then you valve clearence will be out. They should all be set 0.20mm cold

all the push rods look straight. thers sum considerable damage to a couple of the piston faces. nothing to worry about i dont think but a couple are pretty scored so whateva they hit is definatly not gonna be ina good way!! pushrods are all straight. so guessin its all been replaced.