Pitted Engine Block 190e 1993 1.8 Auto

[jon rennison]

all right, I've got a 190e 1.8 auto that's leaking oil into the water cooling system, took head off as was sure was head gasket that had gone, it had but unfortunately this has caused corrosion to the block, worse pitting is about 0.25mm deap, cylinder head is pretty much spot on.

anyone got any ideas on what can be done to fix this problem? I'm thinking along lines of having to take block out and have it skimmed but how much can you have skimmed off as pistons seem to come right up to the top of the cylinders......

 

[NormanB]

I think you may be in deep dwang there!

There are processes that can be applied to the block to fill and seal the pits prior to a teensy weensy (like micron) grind to restore truth and flatness.

However for a car engine block it is probably uneconomic when you could pick one up in a scrappy.

You could try Crewe Engines (Google it) to confirm the above and get an idea of likely costs.

 

[guydewdney]

for the fun of it - i'd try araldite...or similar metal impregnated epoxy resin. fill pits, leave to go hard, very very flat block (piece of glass is good) and fine sandpaper to egt flat agin. the rest will be taken up by the head gasket.

think about it - you have nothing to lose - if it doesnt work, it blows a head gasket again. if it does work, then :bannana:

in future, make sure you use the right amount of anti-freeze - cos it includes anti corrosion stuff.

 

[l5foye]

Pitted Engine Block

Following the last suggestion, try Devcon ( one of the liquid metal mixes) When it sets, treat as you would metal. I heard of a character who fitted a wooden piston to a car- yes- wood- and it lasted a year before breaking up!

 

[guydewdney]

that was the stuff i was trying to remember



i heard of a guy (mates dad, woodwork teaher) who put a woodedn (oak) piston in a 250 cc old brit bike... saw it running round for years afterward (when he sold it 30 seconds after fiting it.)

 

[andy_k]

devcon works a treat. I used it on a friends Rover V8 engine which had the same problem as yours and it's still running now - 6 years and about 50k miles down the line.

As with all filling jobs, preparation is the key, take your time and the repair will cost you a few quid rather than a few hundred.

Andy

 

[jon rennison]

cheers lads devcon sounds like the way forward, beats having to pull the block out, think i'll stick to metal pistons though!

 

[jon rennison]

was the rover v8 aluminium? the mercedes one is cast iron, on the devcon website they have products for aluminium but not for cast iron...any one reccommend any other products?

 

[NormanB]

was the rover v8 aluminium? the mercedes one is cast iron, on the devcon website they have products for aluminium but not for cast iron...any one reccommend any other products?

Hi Jon

Seems as though you are up for it

In that case I would use this Devcon product - called PLASTIC STEEL® PUTTY (A), my only reservations with these products is - as Guy mentioned - you need scrupulous prep ( and protect any oilways and the bores etc while you clean, apply and fettle) - and their ability to cope with operating temperatures. The technical data indicates this is rated at 120 deg C - so it should be OK. But I would give them a bell and discuss:

DEVCON
Brunel Close, Park Farm
Wellingborough
Northants
NN8 6QX
01933 675299
01933 670800

You may also wish to discuss where to source it locally and min quantities I would not have thought you want any more than 250grams. I have no idea of cost.

Good luck and let us know how you get on.

NormanB

 

[jon rennison]

cool, will keep you posted

 

[jon rennison]

Engine has now been pretty much completely re-built, much fun was had taking out timing chain cover pins!!

The pitted block, ended up taking engine out stripping down and getting block cast iron welded and skimmed( firm in cardiff that local mercedes dealship uses, did a very good job), how hard is is to get the dip stick tube out!, they did the head as well just to be sure.

car now running, no oil in coolnat for the first time in a while...

only problem now being that sometimes when it slows down it cuts out / stalls, can restart imediately or take about ten minutes of trying, any ideas as to reason / solution?

Cheers for all your tips and help, most appreciated.

 

[Robby]

Could be running lean if its cutting out while its slowing down and your foot is off the throttle, and a lean mixture can make starting hard. Try getting the exhaust emissions analysed and see.

 

[jon rennison]

the funny thing is that for an hour or so thers no problems at all, then out of the blue, whilst doing same kind of driving, slow down for a junction (usually busy) the revs go really low and it cuts out....

 

[Robby]

Could be a sticking idle controller - its the weak point of the 190E fuelling system.

I'm not sure how it works on the 4 cyl ones, but it will be a device in close to the throttle body with two rubber tubes going onto it. It controls the amount of air getting into the throttle body at very low revs when there isn't enough airflow past the airflow meter to be smooth and consistent.

Remove it, spray in lots of WD40, and ideally let it sit in a jar with lots of WD40 for a couple of hours to really penetrate into it, and occasionally operate it a few times by putting 12 volts across the terminals.

This method worked nicely on my 2.6 with the good size rotary idle actuator. I think yours is a slide type one, which explains it sticking at any revs. 2.6 one just sticks open, giving you a high yet weak tickover.

 

[jon rennison]

cheers Robby will look into that.

 

[jon rennison]

Reckon now that its the lambda sensor, on the service sheets its been cleaned 3 times, the cars done 130K miles and it looks like its never been changed. When the head gasket went at about 90K miles reckon it must have got a fair amount of oil going past it. if you're lucky apparently you get 100K miles from them, the stalling problem is intermittant and the voltage testing that we've done on it gives intermittent results, the stalling problem occurs when engine is hot, i.e when the lambda sensor kicks in. When we removed it and cleaned it then put it back problem was worse, it was the only part of the system we've altered.

Not 100% sure and don't really want to shell out £70 odd quid for new one without being 100% but reckon I'll be replacing the little fella.....

 

[Robby]

You can get testers for them for about 20 quid, or if you ask nicely your local garage might test it for you.

 

[jon rennison]

had it tested at a garage out of the car looking at the change in voltage whilst heating up with butane flame and then fanning it over, results wern't conclusive. can't get car to garage to try it in situ but when tried it with a voltmeter it had inconsistnat voltages

 

[jon rennison]

Lambda probe replaced, £52, cleaned and adjusted the wires on the group of sensors that sit on the nearside wing, don't know what they do but guessing some kind of heat sensing, after some initial stalling problems its no longer hunting or stalling. It doesn't drink as much petrol, as you would expect with a more accurate mixture going through.

Grinding the valves has also given an extra zip to performance.

Cheers for everyones suggestions / help.