Im working on a nice 350SE that has run for a long time with no anti-freeze. Today I removed the inlet manifold for the following reasons :
a) the steel heater pipe under the inlet manifold was badly corroded
b) lots of vacuum leaks -
The heads have previously been removed on this car, and the reassmbly work was pretty poor. Some of the inlet manifold bolts were finger-tight, the rubber boots not properly seated etc etc.
Anyway, with the manifold off, I found this :
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN5613.jpg)
See those brown streaks running down the vee..... do we have head gasket leaks here or not?
left bank :
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN5615.jpg)
And a close-up, with the camera placed in the bottom of the vee, looking up at the underside of the left head :
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN5617.jpg)
right bank :
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN5614.jpg)
And a close-up, with the camera placed in the bottom of the vee, looking up at the underside of the right head :
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN5619.jpg)
Opinions please guys - those are streaks from rusty dirty coolant, but I wondered if its old marks, or who knows? Ominously, they are located at the position of the water channels in the head gaskets....
Its probably wishful thinking to presume I could just try retorquing the head bolts?
BTW today I had only two sheared off manifold bolts - the front most one on each of the two sides. I've progressed well with drilling them out, I will finish that job tomorrow.
Quote from: s class on 05 February 2011, 01:06 PM
Its probably wishful thinking to presume I could just try retorquing the head bolts?
I think if I was presented with that situation I would have to pull the heads and fix it properly, really depends on what the owner is willing pay.
Might get away with retorquing the bolts and maybe a can or two magic leak fixer, who knows.
koan
I would assume if the owner didn't pay for coolant he may baulk at a full head off rebuild.
I would be more interested in history - coolant consumption, any combustion products in the water - as well as a cpmpression test which is probably not possible now.
I would agree with Koan that it is probably reasonable to fix the leaks you can see, refit the inlet manifold and then re-torque the heads and see what happens but with the the strict understanding from the owner that more work may be required after the motor is reassembled if there are
1) further coolant loss problems
2) Cooling system pressurisation test fails after re-assembly.
3) Problems with compression test
4) All of the above.
Bill
Thanks guys. The present owner recently bought the car from a collector. He has only done about 500km since buying the car, and we can't make any comments on coolant consumption because there were so many other leaks (split hoses, cracked header tank etc).
THe present owner is not the one responsible for running without antifreeze.
I did do a compression test before I started disassembly. The results were rather ordinary (for an engine with 130 000km), but I dismissed the poor results as being at least in part to sticking rings, because the engine was running VERY rich due to WUR problems. The spark plugs were absolutely clogged with soot.
cylinder dry test (kPa) wet test (kPa)
1 750 850
2 780 800
3 600 800
4 900 900
5 700 900
6 750 900
7 750 850
8 740 780
variance 300 120
I tend to concur with Bill, seeing as it's someone else's car.
The first thing I would check is the torque of the head bolts in the area(s) of the stains. It could also have been leaking from the manifold and somehow tracking along the gasket edge (probably unlikely).
Tim
TJ, there is leakage from the water channels at the front of the inlet manifold, but those streaks down the valley very definately come from the head gaskets.
But I agree with you that I should check the head bolts. Its the only simple thing I can do at the moment. It may not cure the problem, but if I find loose bolts, it will at least help to confirm the diagnosis.
Progress update - I've had a discussion with the owner of the car, and we have decided that I will pull the heads, and see what we find, with the intention of fixing it properly.
Given the low mileage of the car, I would like to think that the bores will be good, but one never knows. I will soak the rings in ATF while the heads are off in the hope that we can loosen them up a bit.
Sounds like he really wants to keep the car and look after it which is great.
I hope water hasn't got to that No 3 cylinder.
Bill
Agreed, the compression results on #3 are very poor.
I'm thinking along the lines of Bill. If there was water leaking into #3, it could be a situation not unlike my 190E. That engine only has 120,000km on it, however as a result of the blown gasket it now has second oversize pistons in it.
Fingers crossed this isn't the case here.
Tim
Today I removed the heads, and I'm afraid it was a tale of the good, the bad and the ugly.
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN5940.jpg)
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN5941.jpg)
The good : I had NO broken exhaust studs or head bolts.
The good : the heads have been replaced at some point and they are actually pretty good.
The bad : the heads a date coded 1976, and this car is a 1980, so this is confirmation of the head replacement. I believe I found the reason for the head change - this engine has jumped its chain in the past. There is evidence of the chain having run against the dowels of the guides, and a few other places.
The really bad : the person who fitted the 1976 heads retained the 1980 cams and cam towers. THis is evident because there was a change in diameter of the cam oiler line. The small bore 1976 oilers had been fitter onto the 1980 towers intended for the large bore oiler. The plastic oiler fittings seem not to have been changed, and were fitting loosely onto the cam towers. I just picked up the oiler off the towers without any pulling force. :o
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN5942.jpg)
The really, really bad : with all the rockers removed, the cams were impossible to turn by bare hand. It required a spanner on the sprocket retaining bolt, and considerable force on the spanner to turn the cam. Obviously the tower bores are misaligned due to swapping heads but not pedistals.
The ugly : with the heads off I found this :
All cylinders : a very obvious lip at the top, easily felt with a fingertip (even after cleaning the carbon off). There is no evidence of hone marks anywhere. the cylinder surfaces are completely glazed.
Cylinder 4 :
This area of scoring is easily felt with a fingetip. It feels like coarse sandpaper actually.
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN5944.jpg)
Cylinder 3 :
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN5945.jpg)
The carbon deposits extend well below the ring lands at the rear of the bore. So the first one or 2 rings are either very stuck or they have lost their temper.
Itsounds like you are not finished yet.
Are there many second hand 350 motors about or is it possible to upgrade to a 450 motor?
A full re-build of that one will still mean looking at the heads plus ?that motor almost appears to have seized at some stage.
Bill
That is disappointing, it sounds like the motor has been cooked.
Tim
Certainly this is disappointing. Are you saying that those score lines are from heat seizure?
Quote from: s class on 20 February 2011, 11:30 PM
Certainly this is disappointing. Are you saying that those score lines are from heat seizure?
That's what it looks like to me - either complete or momentarily and then put back into action as cheaply as possible without even the correct coolant.
It will need a lot of work to get that motor to work as well as it might.
Bill
Used motors are available, somewhat. 350 engines are around, but will all be very high mileage units needing rebuilding anyway. A 450 engine can be had from a 450SLC (we didn;t get 450SE/L), but again it will have at least 200 000km and be pretty much unknown.
At this stage I think we are better off sticking with what we have rather than taking a gamble.
I am sure when you have finished it will be perfect.
That's the line I have been trying to take fix it properly once and it may last another 30 years.
Bill
I've just discovered some not-so-nice prices.
Pistons are about $450 each for std or 1st oversize, 2nd oversize is NLA.
big end shell set is $320
mains are $180
thrust bearing is $140, and only 4th repair size is available.
block gasket kit is $407.
Add to that head gasket kits, chain, guides, tensoner for another $300 or so, and lots of engineering to fix the block, get the cam pedistal to head interface problems sorted and this is adding up a bit.
Wow, those piston prices are nearly as much as for the M100 equivalents, if I remember correctly.
Are these dealer prices? If purchasing from the US is an option, you could try searching for the part numbers at World Impex. They will order in genuine MB parts and seem to be cost effective for most things. I have ordered my 190E engine parts from this mob, and I have an engine that was never sold in the USA.
Tim
Yes, those are main dealer prices. I thought I would start there to see what they want for all the goodies. Obviously those piston prices are prohibitive, so I am looking at alternatives.
there are a few on ebay.. mostly in germany so postage is realy going to hurt..
bad luck. :(
Link (http://cgi.ebay.co.uk/W107-Motor-M116-350-W116-W108-W109-W111-/350290039452?pt=Autoteile_Zubeh%C3%B6r&hash=item518ee9d29c)
Thanks, but importing a whole motor is just not going to work. I am going to approach our local alternative-channel engine parts supplier A.E. www.alertengineparts.co.za (http://www.alertengineparts.co.za)
Finally an update -
Pistons are NLA from MB - that includes standard, 1st and 2nd oversize. Mahle and KS couldn't help either. We ended up sourcing good used pistons from a donor engine, and sleeving the block back to standard. I finally have the subassembly back from engineering :
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN1733.jpg)
It cost $2000 to get to this point.
I spent another $1000 on gaskets, chain, sprockets etc. I still need t have the heads engineered, and the anticipated bill there is about $750 for the two.
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN1735.jpg)
Thats the donor engine block also loaded in my trailer
(http://i54.photobucket.com/albums/g85/mercedes_s_class/116028/DSCN1734.jpg)
And the rest of the donor engine.....
Bloody hell what a shitfight!
The good side is that the engine will outlive the car.