Head Gasket Issues

[colin evans]

Good luck Dave, let me know how it goes.

[Benz Dr.]

No need to drain coolant while you re-torque the head. Do each head bolt one at a time and you should be fine.

We have any corrosion around water ports welded with aluminum and then the head can be milled flat. A head gasket needs to compress against a solid base so that the head and block will form a flat surface by which the gasket can seal. This is where leaks occur.

[Pagodateil]

Hello I think the problem is the head cylinder there is to type of them one goes on the cylinder casing with two little hole per cylinder and the other have none in order to solve this problem I bloked this two holes with some plug

[Dave H]

Hi Colin
No luck, just run the car after changing the head gasket and it’s been a waste of time, still smoking like a ten year old on a school trip. I guess I’ll be looking for a reasonably priced 280 cylinder head .
Hope you have success with yours .

[colin evans]

Thanks Dave, what a shame. Best of luck with the search.

[MikeSimon]

Hello I think the problem is the head cylinder there is to type of them one goes on the cylinder casing with two little hole per cylinder and the other have none in order to solve this problem I bloked this two holes with some plug

This is a remote possibility, but still worth confirming. The two different head gaskets go on different heads. But they also go on different blocks. The earlier head/gasket with the "square" shape combustion chamber goes on engine serial numbers manual up to ..5301, automatic up to ...8784. The later head/gasket with the "oval" shape chamber from serial number manual 5302, automatic 8785. If the head was ever replaced and the wrong head fitted, there may be an issue. The head gasket may be correct for the head but the head and gasket could be wrong for the block. And for the later head/block, there is also a different gasket for first oversize. MB part-number 130 016 5520

[colin evans]

Thanks, I will definitely check it out, although the gasket I fitted did look to be correct.

[MikeSimon]

It is easy to tell if the gasket is correct for the head, but a little more difficult to see if the head and gasket fit the block. There will be a few openings/holes that are different. Check the serial number of your engine.

[Dave H]

Hi Colin

How are you getting on, did you manage to fix it .
Like you i have the late 280 motor with the oval combustion chambers.
Regarding the head gasket ensure you have the correct one.
Part numbers.
 A1300165520 is for standard and up to repair size 1 ( 86.5 - 87mm).
 A1300165620 is for repair size 2 ( 87.5mm).

Reading previous posts has caused a lot of confusion, wrong part numbers and misinformation exists around this point however it clearly states the 2 repairs sizes in the EPC.
If somebody else can confirm this as 100% accurate please do, and i will then either alter or delete this post to avoid any future confusion going forward.

[colin evans]

Hi Dave
That was good timing. I got back on the road yesterday, and (fingers crossed), all seems ok. Did around 20 miles with no overheating and no smoke whatsoever from the exhaust. I had a bit of a miss on the way home but it was a scorching day and I had purposely left the manifold heat shield off as I had a slight exhaust blow to look at later, so most likely that was a fuel issue. I double checked and the gasket I fitted this time is A1300165620 - although I am not sure what the first failed one was. What does the 87.5mm refer to?
I'll change the oil in 50 miles or so. Anyone any recommendations for the best oil to use?
Thanks, Colin.

[Dave H]

Glad to here your back on the road.
87.5mm is second repair, i had mine bored out to this size and fitted second oversize 87.5mm pistons.
Confusion over part numbers lead me to order the wrong gasket twice, i believe its one of the reasons it failed, that plus the fact  the head had been previously machined down to 83mm which would raise the compression.
Further to this the water ports still have corrosion around them which didn't help and i cant skim the head any further.
I have sourced another head at stock 85mm which i intend to weld build up any corrosion around the water ports and skim to a perfect finish. Hopefully this combined with the correct 87.5mm gasket will solve my problems.
Im working crazy hours at the moment but intend to sort this work out mid July to allow me back on the road for August.

[colin evans]

Well done Dave and good luck with it, glad you managed to source a head ok. The 87.5mm is odd as I have never had a rebore and I am pretty sure the first failed attempt used the same number gasket. But it seems to be ok at present, I guess more miles will tell. Let me know how you get on.

[Dave H]

From the Epc, it shows the part numbers for first and second repair.

[colin evans]

Strange, I think SL shop only offer the oversize one. Anyway it seems to have worked fingers crossed!

[Dave H]

As far as i can ascertain both Gaskets are available however.
A1300165520  Stock to repair 1 .Discontinued, a few remaining old stock gaskets possibly left, available for like £500 ( google the part number)
A1300165620  Repair size 2 .Widely available as it’s the only size produced today by Elring for the 280 oval cylinder head. ( Elring passenger cars catalogue download, volume 2 page 568 )

So...unless they start making them again the only choice today is to use a gasket, that was originally designed for repair size 2.

[Kevkeller]

Dave,
Did you recheck the compression?  If it’s still low I’d add a little oil in the cylinders to seal up the piston rings and retry the test. If the pressures are much higher it would show your rings are bad.

Kevin

[colin evans]

Hi Kevin
Re-checked the compression, all now between 120 and 130 dry. Still on the low side but a decent increase on what I had before and all pretty close. I haven't tested wet as I know it will increase a little, it always does and I don't have any symptoms of the rings being worn, so I am leaving well enough alone at present!
It is still a mystery as to why the replacement gasket failed. One interesting thing is that nobody on here could give me torque settings for the 4 small bolts at the front of the head, a couple of people advised to just tighten by hand. The actual recommendation is 25NM (19ft lb), which is definitely tighter than I would have done by hand, in fact it is quite close to the max for a standard M8 bolt.
Regards Colin.