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200tdi decapitation

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200tdi tdi
10K views 78 replies 11 participants last post by  sonoronos 
#1 · (Edited)
Just a thread on working on my 200tdi.

(Don't mind the pushrods in the head. One of the bolts holding onto the rocker shaft stripped the head and I'm still trying to remove it.)

Not sure what happened but the truck has been quite down on power for years. I checked all the usual bits, set the FIP timing on the dot, put in a fuel pump, Everything was spot on, nothing was amiss.

I completely rebuilt the turbo, sandblasted and ceramic coated the exhaust header and downpipe, new exhaust/intake gasket, etc. Still no change in performance.

Oil mist has been steadily blowing out of the dipstick tube. It couldn't have been much because I have not really been losing a noticeable amount of oil. Long term observation of the oil filler cap on the head while running has shown no pressure coming out the valvetrain. No pressure blowing out the cyclone. Still, the oil coming out of the dipstick tube was a little concerning.

Coolant leaks have been an issue on the truck for a while: mystery coolant loss, nothing amiss on the truck, so I just filled the coolant regularly. On the last wheeling truck up to BDO at the cove, I realized that faint steam was coming out from under the bonnet.

When I popped the bonnet, I found that the interface between the thermostat housing and the head was spraying coolant in a fine mist. Had to carry several gallons of distilled water with me on the remainder of the trip home, filling up the coolant along the way.

Took off the head, expecting the worst, actually found the head in good condition.

During removal of the head, some of the head bolts were not nearly as tight as others - these "loose" bolts were near the middle two cylinders of the head on the exhaust manifold side.

Looking at the headgasket, it looks like a bunch of stuff was traveling through the headgasket - coolant, oil, combustion gases - all just kind of leaking around when the engine was hot.

2 of the 8 valve lash caps had busted through the center.
 

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#6 · (Edited)
As far as I can tell, everything is original on the engine and nothing has been worked on. Mikeslandrover could probably shed some light on past history on the engine if he's still lurking :) Quite honestly though, I think he got the engine secondhand and it was a good one.

My theory is that after decades of heat cycling things just work loose, and not uniformly. Once one part gets a little loose in the head, pressure just starts pushing through along with whatever is in it.

Decades of heat cycling, diesel vibrations, etc. just take their toll. I can't help but think that me only driving this thing for short trips here and there exacerbated the heat cycling.

Nothing lasts forever, the gearhead's fantasy is that an "engine done right" will last forever. Not hardly! Everything requires maintenance. I really felt true fear pulling the head. I had nightmares of cracks everywhere. :(
 
#7 · (Edited)
Congrats on the good luck. Get the nuances sorted, get the head cleaned up and you will be back better then ever.

I see some VW lash caps in your future
https://www.ebay.com/itm/VW-BEETLE-...171432167569?_trksid=p2349526.m4383.l4275.c10

When you have a chance, can you take a pic of your valve spring retainer tops? I have what looks like wear on mine but can't tell if its just from casting/manufacturing. Machine shop thinks its just "how they are". I've had new springs/retainers/seats sitting in a box for a while but just don't feel like swapping them out. Supposedly it can be done with the cylinder head installed if you put the piston at TDC to keep the valve from dropping.

Not my pic but they look like this...
 
#8 ·
Adam, yes that is how they are. Every 200/300 engine I've had apart has had this pattern.

The lr lash caps are criminal, when rebuildinf this head... If you reuse the valves you should have the tips machined for mushrooming since the cap was gone. Or just replace them.
 
#9 ·
If the lash caps are worn, the head has been worked on at some point. The original lash caps do not wear out. It is only replacement ones that have the problem.
 
#11 ·
My engine with god knows how many miles has the original caps. They have no wear. I suppose if the engine was very poorly maintained they would wear, but so would the rest of the engine. the original ones are hard as a rock and to be worn out as shown, the rockers would be gone as well.
 
#13 ·
to be honest, it would be pretty futile to guess at the history of the engine. The best way to find out without a fight is to PM mikeslandrover :)

i'll keep posting pics as requested, thanks everyone for the tips on fixing it up - re: lash caps, etc. no idea on the valve stem seals yet as I am waiting for my valve spring compressor in the mail :)

I'm mostly curious about who should skim the head here in northern virginia?

also, should I just send this thing into turner's in the UK and have them do the valve guides, etc?
 
#19 ·
Ed, two very good machine shops in nova, they have performed very well on a variety of european engines I have commissioned for my past customers including Pedro....

Pete @ Bimmer's unlimited in arlington at 4 mile run and walter reed drive and Russel @ Allied machine shop services in falls church behind Don Beyer Vulva off rt 7.

------ Follow up post added November 16th, 2017 04:13 PM ------

sorry "VOLVO" frigging auto spell....
 
#14 ·
Yes, I was just making the point that the engine has more than likely been apart. That is the most likely cause of having loose head bolts. With the stretch bolts, they should never "work" loose.

Pull the tappets and have a good look at them. Some of the aftermarket ones are made out of cheese and if they were replaced "out of course" like the valve caps may have, they are worth looking at. Gives a chance to look at the cam as well.

On the coolant loss issue, I had loss from the gasket between the block and the timing case. Look closely there. The problem is that when you remove the water pump to get the timing cover off, it releases the clamping on that gasket. It is not the greatest design in engine history.
 
#15 ·
On the topic of coolant leaks around the thermostat, anyone had trouble with the seal around the actual thermostat? I'm on my second gasket and it still seems to be leaking. Granted my situation might be a bit different as I'm using the cap from a Series and the frontmost bolt runs out the bottom, but still seems like I should get a solid seal. I'm considering wet sanding both surfaces on a flat plate to see if that helps, and/or put a nut on the bolt that runs out the bottom.
 
#17 · (Edited)
On the topic of coolant leaks around the thermostat, anyone had trouble with the seal around the actual thermostat?
I've never had a leak there. I also use silicone and not the original paper gasket on that interface.

I would try using good silicone gasket maker instead of the paper gasket there.

I should elucidate: I have removed the valve cover and changed the valve cover gasket once. I have been checking the valve clearances every year. I have never changed the lash caps myself. I don't know when they cracked because I never examined them that closely when I was running the valve clearances. it's possible that when I was checking valve clearances, the caps were already busted.
 
#24 ·
clean your pistons and check your tops, Pedro's old 19j had hairline cracks on the piston crowns. reason he replaced the engine.
if such is your case then you have a further decision to ponder, overhaul with new pistons or source a "new" replacement, be it 200 or 300 upgrade.
 
#25 · (Edited)
no hairline cracks on my pistons....but really...hairline cracks on piston crowns? No wonder why LR switched to the 200tdi...

I just feel like the 200tdi and the 19j's are totally different engines. Running non-intercooled boost on what seems like ancient piston alloys with poor head and block cooling just sounds like a bad combo. i wonder if the 19j's lived longer if you just ran them NA.

then again, i shudder every time i hear about people worrying their 200tdi's "running too cold" (on an aluminum head?) and "wanting higher egt's" (again...on an aluminum head with thin cast walls?). The secret to longevity is to push the engines as far away from the limits as possible, not ride at the top. :facepalm:
 
#29 ·
I agree totally with your observation and yes the 12j aka n/a, is the non turbo19j.
on the head, of course the valve guides are one of the most abused components in the cylinder head. continuos heat and pressure, little to no lubrication. shoot why Im I exposing these issues?, you're a very smart engineer, you know what happens inside a combustion engine...lol.

and yes hair line cracks ....lol...one think #3 was missing a piece of the piston top possible due to continuos and excessive lean mixture.
in any manner is water under the bridge, replaced and done...

great job on putting your engine on the guillotine.

C.
P/s you know I must give you grief.:rofl:thumbs:toast
 
#27 · (Edited)
Measured component wear:

Cylinder 1:
Valve 1 (exhaust):
Top: 7.94mm
Middle: 7.93mm
Bottom: 7.94mm
Valve Guide Play: 0.381mm / 0.015"(total) *exceeds 0.15mm max spec*
Valve 2 (intake):
Top: 7.94mm
Middle: 7.94mm
Bottom: 7.94mm
Valve Guide Play: 0.1016mm / 0.004"(total)

Cylinder 2:
Valve 3 (intake):
Top: 7.94mm
Middle: 7.94mm
Bottom: 7.94mm
Valve Guide Play: 0.1524mm / 0.006" (total) *exceeds 0.15mm max spec*
valve 4 (exhaust):
Top: 7.93mm
Middle: 7.93mm
Bottom: 7.93mm
Valve Guide Play: 0.1778mm / 0.007"(total) *exceeds 0.15mm max spec*

Cylinder 3:
Valve 5 (exhaust):
Top: 7.92mm
Middle: 7.92mm
Bottom: 7.92mm
Valve Guide Play: 0.1524mm / 0.006"(total) *exceeds 0.15mm max spec*
valve 6 (intake):
Top: 7.95mm
Middle: 7.95mm
Bottom: 7.95mm
Valve Guide Play: 0.0762mm / 0.003"(total)

Cylinder 4:
Valve 7 (intake):
Top: 7.94mm
Middle: 7.94mm
Bottom: 7.93mm
Valve Guide Play: 0.1778mm / 0.007"(total) *exceeds 0.15mm max spec*
valve 8 (exhaust):
Top: 7.92mm
Middle: 7.92mm
Bottom: 7.92mm
Valve Guide Play: 0.254mm / 0.010" (total) *exceeds 0.15mm max spec*
 
#30 · (Edited)
thanks carlos, appreciate the info and occasional jab.

I just ordered the following parts for the rebuild.

The most expensive parts? The rockers (about $90 for all 8) and the exhaust valves (ordered genuine LR since these experience the most abuse - $88 for 4(!!))

It's amazing how much everything was worn out in the head in this engine.

My recommendation to anyone buying a used rover with a 200tdi with unknown miles? Inspect the head before you start putting it through a lot of use...at least take the rocker shaft off and inspect the pad wear. If you see noticeable pad wear on the rockers or a busted valve cap, your head is probably going to be in need of a refresh soon!

 
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