Peugeot 405 1.9td very smoky and idle jumps

[CitroJim]

Valve clearances look OK. They would only be a problem if they are very tight and you would be unable to insert even your thinnest feeler gauge. Slightly wider than specification clearances are unlikely to be the cause of your problem.

[TimDonovan]

Sticking valve, valve stem seal or what are your thoughts on the smoke from the intake?
That is really worrying me....

[CitroJim]

Yes, as I said earlier, smoke from the inlet is a concern and indicative of a leaky inlet valve.

If your engine was a much later one I'd have suspected the EGR valve but yours is too early to have one. Do check there's nothing connected to the inlet manifold that might allow exhaust gasses in. I can't think of anything off-hand...

[TimDonovan]

Got my hands on a compression tester and leakdow test.

I did all the test on a cold engine bear in mind.
I compression tested it twice because I couldn't really belive the 35odd bars of compression compared to the other which are in the Haynes specified speck, so is 35bars as the max compression value. But my engine was cold about 35°C outside temp and is just too high.
What I noticed while compression testing the other cylinders is that cylinder 4 or closest to cambelt what puffing out some smoke of sorts. So i unbolted the glow plug cable and held a white rag infront of the injektor hole while just cranking the engine. It wasnt as black as i would expect oil but no distink taste or smell of coolant.
So I did a leakdown test.
Cylinder 4 which had the highest compression had the most air escape out the valve cover vent. All 3 other cylinder had reasonable air loss for a cold engine.
No air bubbles in my coolant reservoir tho, on all cylinders. I was only running a 8bar compressor. I had bubbles in my coolant while it was idling before I did the test which is confusing.

So what is going on, it must be trying to compress something I'm guessing coolant in cyl.4 hence the white smoke and bubbles in reservoir. I couldn't esle explain the high compression but high leakdown through valve cover.
Cracked head?
Very very weird I'm guessing it's a head of type of job from now on.

[CitroJim]

Shows the value of a leakdown test... Yes, definitely now time to whip off the head and take a look.

A crack is unlikely. The gasket having failed is the most likely issue. Do have the head lightly skimmed and properly pressure tested before reassembly.

[TimDonovan]

Giving me atleast a bit of hope
I'll try my absolute best to evenly crack the head bolts open and not to warp it.
I was already expecting a head gasket tbh, so I already did some research, I heard horror stories of having to adjust valves with cam clearance and different swirl chambers after getting it skimmed at mashine shop.
Definitely will Grind valves seats and valves and do valve stem seals while the head is off.
Choosing headgasket will be the next adventure with measuring piston petrusion.
Had a bit of trubble finding new head bolts, any suggestions on where to find some decent ones, really don't whant them snapping.
You can apparently measure the bolts, Mazda does that too but I'm not a big fan of that.

[CitroJim]

No, best to use new head bolts and a repair gasket, which is a little thicker than standard. If the machine shop takes just a light skim to clean up the face then pre-chamers will be good to go again and the valve clearances should remain in spec. even after a light lapping-in.

Do check the pre-chamber mouths for serious cracking.

[TimDonovan]

Ok, got the head off.
As expexted cylinder 4 has some serious build up and on the added pictures you can see the black spot where I suspect the water was getting in.
There was a shocking amount of rust on the headgasket around the coolant passages. I don't suspect it to be a multi layered steel gasket.
What are your thoughts. I'll clean it all up and check the head and block for warping and cracks.

Any suggestions where I can buy headbolts and the spacers is well appreciated.

[TimDonovan]

Ok, just looking at the head, I've noticed something very strange....
Notice that round hole ? It's on the cylinder with the coolant leak.
Are these original, I can't belive that, but it looks so perfect it could be oem. No other cylinder has this tho...
Maybe that is why I had so much blow by from my valve breather ?

[TimDonovan]

Ok new update, cyl 4 has a cracked pre chamber.....
Also it's loose in the head I can move it around and liquid squishes out at the edges
What's next step, new head ?

[darbuck]

You might be able to get the head repaired failing that you will need a replacement.

[CitroJim]

Those little cracks are not serious, nor a problem and you'll find most heads have them after a few years... Also, the chamber being a little loose is not a problem either. It won't be when it's clamped up when the head is refitted.

Worry no more

Have the head crack tested and very lightly skimmed before refitting.

[darbuck]

Interesting good to know Jim

[TimDonovan]

Thanks for the replies and the hope!
I will try and get it xrayed and skimmed.
Im just a bit concerned about that loose swirl chamber beeing the part where my leakdown test blew of into my valve cover. Leak inbetween chamber and head.
I read up on swirl chambers and I read one source that a pre chamber is supposed to extend over the head 0.02mm for the clamping effect, that was unrelated to peugeot though.
All other 3 are tight and had no leak down,
I guess the xray will give me a conclusive answer.
Still no one got any suggestions on where to get head bolts and especially those spacers which Haynes especially mentions to be replaced ?

[xantia_v6]

Any suggestions where I can buy headbolts and the spacers is well appreciated.

What about https://www.mister-auto.com/gv/boulon-v ... /405/2384/ ?