Help with smokink DW8 Xsara after Head Gasket change

[xsaras4ever]

Hello to the forum from France. First posting, though have read loads of great advice on here.

Any advice welcome on our smoking smoking smoking Xsara.
Here is the full tale.

We bought a Xsara estate(1999), 1.9 DW8. It seemed to run on 3 cylinders on startup in the morning, cleared after 30 seconds and didn't re-occur throughout the day. The previous owner said it has been like that for 2 years and his mechanic suggested it was a problem with one of the injectors.

The car ran well, did not smoke, but we found it as slow as a previous 1.9 XUD Citroen ZX estate which we owned, unlike the Xsara HDI and 1.9TD we have had.

We were doubtful that it was an injector but we had a spare set which we fitted, but the problem remained , which confirmed our theory that it was a valve-stem oil-seal problem which seemed likely as one injector was oily when we removed it first thing in the morning.

We put up with the inconvenience for 3 weeks and the car was reliable.

We then loaned the car to a friend for 2 days, and we suspect that he drove it hard.
When we had it back from him it ran fine, did not smoke, but he mentioned that the electric radiator fan did not work.

We did about 100km of driving, everything good.
We then decided to have the head off and do the valves.
We ordered a head gasket set with a slightly thicker gasket, new bolts ,new filters , timing kit and aux belt.

Wish we had got the head checked !!!!!!!!

Removed the valves, ground them in very mildly, fitted new seals, refitted head. Wow , last did a head gasket 20 years ago on a mini and the amount of force required to torque down the xsara head is a hell of a lot different than that !!!

Had marked old timing with tippex. Fitted new timing kit and aux belt.

Car started fairly easily, mildly misfired and smokes, whitish grey. It stank, so most likely diesel.

Took the evening off to mull it over.

Next morning checked timing by locking cam, pump and flywheel. It was perfect but took the belt off and refitted with system locked, just to be sure.

Still smokes hugely and mildly misfires. Gets worse if left running for about 3 minutes until it wants to die, though we kill the ignition before it labours too much.

Soulds like unburnt diesel filling the bore ?
Changed the injectors back to the original ones , still the same problem.

Is it a warped head - could be caused by our friend and the fan not working - though unlikely as the car ran well when he returned it.

Thicker gasket ? Pump need adjusting because of a change in compression ?

Sticking/slow valve ?

Help !!!!!!!!

PS: We actually hate this particular Xsara - its the base - base - base model and no improvement on the ZX. Our son bought a DW8 Xsara Estate a few weeks ago and its great, but ours is a rice-pudding truck.

[Peter.N.]

Did you have the head machined? If not by fitting a thicker gasket you have lowered the compression ratio, how much thicker was it?

Peter

[xsaras4ever]

Hello and thanks for the quick reply.

Didn't get the head machined, so yes , most likely changed the compression.

As far as thickness is concerned, the old gasket is the original , the head has never been removed.

The original gasked has 6 holes on the id tag, the new one has 2 holes.

The label on the packaging is faded but it looks like .42mm thick. It also says EHG.460C.

Would it account for the problem ?

Better to change the gasket rather than play with the pump ?

Thanks Again

[wheeler]

Did you check the valve clearances before refitting the head ?
You cant play with the pump timing on a DW8, no elongated holes. The pump timing is set by locking it with the pins.

[jgra1]

could be worth doing a comp test on all cylinders .. may give up some clues

[xsaras4ever]

Hello again,

New gasket is 1.50 mm thick

If the old gasket is 2+4 hole and most likely original ,is that the .84mm thick one ?

Didn't check the valve clearances, but on an overhead cam engine they shouldn't move enough to be a bother.
The valves were ground in by hand with mild gringing paste, and it actually looked like it had no effect - removed nothing from the valve seat.


Thanks

[jgra1]

I don't think the gasket thickness is the issue.. I changed mine for a thick one a few years ago on a TD and it was fine..
it does sound a bit like timing out or one cylinder has a problem.. but I know you rechecked timing ..

[xsaras4ever]

Hi ,
will do a compression test.

BTW, the old gasket is stamped

CURTY PAYEN
96 248 521 80
18 C 9

I cant track this down anywhere on the net.

Thanks

[wheeler]

Didn't check the valve clearances, but on an overhead cam engine they shouldn't move enough to be a bother.
The valves were ground in by hand with mild gringing paste, and it actually looked like it had no effect - removed nothing from the valve seat.

If the camshaft was disturbed then I would deffo check the valve clearances, even more so seeing as you had the valves out & lapped back in. I'd there any possibility any of the shims could have been mixed up & now back in the wrong place ?

[xsaras4ever]

aha.

First answer would be no, they didn't get mixed up because I laid them all out in a line on the bench on clean paper then pushed them to the back out of the way.
But I have a little niggle that I knocked into one and then put it back in line. Maybe one position out !!!


As I havn't got a diesel compression tester and have to wait to borrow one, I am sitting on my hands at the moment so at least checking the valves will be something positive to do.

Sorry I discounted your earlier mention of the valve clearances.

It might be my imagination, or trying too hard to make the solution fit the problem, but.........I am sure I can detect a slight tinkling noise from under the head cover on number 1 cylinder.

Also , I forgot to mention that before starting this repair, there was black oily scum in the expansion tank on the top left of the rad. But the car did not smoke , very clean infact . This scum and the starting on 3 is what prompted doing the repair.

I havn't flushed the system yet, as before doing so I wanted to check that the engine ran well (you wouldl't believe the price of products such as engine-flush in France !!!)

Still oily scum, but not sure is it the old scum coming to the surface or new oil.

Fingers crossed for the valves though.

[Stewart(oily)]

I would remove the rocker cover and check the clearances, my own personal record is having the cam out and back about five times sorting out the clearances on an engine that had broken its cambelt
I would not worry overmuch about driving a DW8 engine too hard, I put 50,000 on one in my works van and I was not gentle with it

[xsaras4ever]

Hello all.

Just checked the valve clearances - not easy with a toy feeler guage with an engine tilted away from you and the valves buried in the head.

All Exhaust valves perfect at 0.30mm .

3 tight inlet valves

No 1 at 0.05mm
No 2 at 0.10mm
No 3 between 0.05mm and 0.08mm

No 4 is between 0.10mm and 0.12mm so passable.

So as there are tight ones and no loose ones it wasn't a mix-up on the workbench, but how the hell did that happen ??

Why is it just the inlet valves ?

I suppose I gotta buy a tool to measure the thickness of the shims and god knows where I will get some - anyone know where I can buy online ?

So the theory is that it is getting too much diesel, causing it to misfire and give diesel smoke, right ?

[Stewart(oily)]

I managed fine with a cheap micrometer, if the shims are the same as XUDs I have salvaged quite a few over the years, let me know what thicknesses you need.

[citroenxm]

A DW8 is basically an uprated XUD, they still use the three breaing cap in head setup, with bucket and tappet shim..

Are all heater plugs working perfectly? Though , on a DW8 the heater plugs are ABOVE the injectors so theres no reason not to do the one by the pump... they are easy to get too...

[xsaras4ever]

Hello again,

I just read an article on checking the shims, and it says allow a tolerance of +/-0.07, which even though the inlets are tight, they are within tolerance. Is changing the shims the "magic bullet" I think it will be, or should I be looking elsewhere ?

Can't see the connection between the heater plugs and the excessive smoke, can you elaborate please ?

Again , thanks to all who have contributed . Its nice not to be carrying a 1.9DW8 around in my head all day by myself.