[sotal]

As a quick recap - I purchased a RR last year with a blown Head Gasket, so it was cheap. The car had been sat for a year with one head removed. I removed the other head and cleaned it all up, there was rust in the bores and it didn't look pretty. All cleaned up very nicely and I fitted the new headgaskets and rebuilt it all back up.

It started first turn of the key and I thought all was good.

I managed to get it MOT'd but it only just passed on emissions and that was only due to me getting the cats red hot before going in.

So on to the problems,

It's using oil on one of the cylinders on the right bank, the spark plug quickly fouls up with oil.
It's running rich on the right bank (according to OBDII fuel trim readouts)
When driven normally there aren't any signs of a problem, but when revved past 2500rpm it gives of clouds of smoke, if you keep your foot down and allow clouds of smoke to be created then after a minute or two it all clears (I presume as the cats are so hot they are now burning it off?)
There are no obdII errors being stored.

Otherwise it's a great drive but MPG is terrible.


I haven't had the time to look at it for the last three months but need to get a move on now, so I was just looking for some fresh ideas. I was going to post what I was going to do next etc and what my thoughts where but it might be best to not influence it, so where would you start what would you be looking at?

Many thanks

 

[Cornishman]

Generally, if the head gaskets let go, the engine has overheated.
You can't just clean the head up, reassemble and expect it to run correctly. The heads have probably warped, which an engineering shop may be able to skim true again(but there is very little leeway).
The bores will need to honed out to remove any rust pitting and then possibly, appropriate oversize rings/ pistons fitting.
If your burning as much oil as it seems, your cats are probably shot, so they won't be helping to reduce the emissions.
As for the fuel economy being bad, it could be a host of things, lambdas, maf, heavy right foot, air leak leading to the system over-compensating.
These are complicated, expensive beasts, and shortcut fixes generally don't get you anywhere :thumb:

 

[sotal]

Thanks the head and block were checked and were within tollerance, I did think about honing but at the time wanted to rebuild the engine to make sure the rest of the car was OK (suspension, gearbox, abs, airbags etc). So I needed to start it up. Now it does start up everything checks out with the rest of the car.

So any ideas on things to try without stripping it down again?

I'm seriously considering selling as is, or breaking for parts just not sure which would be financially better

 

[Cornishman]

As much as it hurts me to say it, the parts on a well known auction site, would probably fetch more than trying to sell it with a broken engine :crybaby2:

 

[allyv8]

If you take off the left head,drop the sump and remove the piston from the bore that oils up - I think you will find that the rings have broken up.There will probably be damage to the piston too.
Saying that,its perfectly acceptable to hone that bore and fit another piston and rings.I've seen secondhand pistons used on sales cars where "margins are poor" with good results.So the costs would be another head gasket,inlet manifold gasket and a piston with rings.If you strip it and its knackered then all you have lost is the time - any buyer would immediately knock loads off for a poor runner,so if its stripped then at least you can see what is wrong.

 

[dave3d]

If you are getting a lot of oil in just one of the cylinders to me it points to either a broken/damaged piston ring or less likely worn valve guides. I would do a compression test on the cylinders. A compression tester is not that expensive and it is a useful piece of kit to have in the workshop.

If the compression is down on just one cylinder you can then test if it is the rings by pouring a small quantity of fresh engine oil in through the plug hole. Then repeat the compression test. The oil will temporarily seal any leakage past the rings. If the pressure is OK, it proves it is the rings.

Dave
:idea:

 

[sotal]

It is starting to make me wonder about breaking for parts - as a rough guess what sort of price do you think it would fetch in parts? or what sort of price for a running car with 9 months MOT but problems with the engine?


As for compression testing, I tested the cylinder which was oiling up, and the results were fine I can't remember the exact result but 160 rings a bell. This was done with just the neighbouring spark plugs removed. I have now removed all spark plugs ready to test all cylinders just haven't got round to it as the battery was then flat.

That will be one of my next things though.

Nobody has mentioned the over fuelling - do you think that will be down to the oil in the cylinder causing it to misfire? Or a faulty coil pack etc? Also could air leaks on the manifold valley gasket cause any problems (was just mentioned by someone)

 

[allyv8]

You only need a partial misfire to make the ecu narrow down the injector pulse width on that bank.When the ecu gets to the lowest limit of fuelling it will still show rich from that oxy sensor because of the misfire - you will then get the "Too rich bank B" fault logged.
The reason the compression is still good on the damaged cylinder is because of the extra oil hanging around in there - squirt oil down any of the other cyls and the chances are the readings from them will go up too.
For the work it involves if you can get away with a few gaskets and a piston it has to be worth a shot.A local breaker to me used to offer £500 for complete P38's for breaking.Remember there is alot of work in taking a car apart,and it will take a while to sell it all.Be alot easier to sell for alot more as a complete useable car.There is a 98 DSE in my yard at the moment which has just made £5000 - good money methinks for what it is......

 

[sotal]

You only need a partial misfire to make the ecu narrow down the injector pulse width on that bank.When the ecu gets to the lowest limit of fuelling it will still show rich from that oxy sensor because of the misfire - you will then get the "Too rich bank B" fault logged.

I'm not getting any faults logged, but the fuel trim on one side goes up to max - it's a few months ago but 25% rings a bell. I swapped the lambda sensors round to make sure they weren't at fault.

Would the oil be enough to cause that partial misfire? Which would then in turn cause it to run rich?

The reason the compression is still good on the damaged cylinder is because of the extra oil hanging around in there - squirt oil down any of the other cyls and the chances are the readings from them will go up too.

Yeah I realise that it is a wet test - but how much should that add to the readings? I had read that a wet test should add 10-15psi, or does that only really apply to healthy cyclinders?

For the work it involves if you can get away with a few gaskets and a piston it has to be worth a shot.A local breaker to me used to offer £500 for complete P38's for breaking.Remember there is alot of work in taking a car apart,and it will take a while to sell it all.Be alot easier to sell for alot more as a complete useable car.There is a 98 DSE in my yard at the moment which has just made £5000 - good money methinks for what it is......

Yeah it would be best to get it running right but I feel I am flogging a dead donkey here, and time is in short supply at the moment. Been doing a lot of house alterations which has eaten up all my time, and has filled the garage with supplies etc so it's down to working on the drive now

I don't mind slowly taking bit by bit off and selling on ebay to slowly claw back the money, but I'm just not sure if it will be worth it:

The bits which spring to mind as having any value are:

Leather Interior Very good condition
5 Alloy Wheels - 4 with very good tyres
Gearbox
Axles
Doors
Lights
Steering Wheel/Airbag
BeCM + locks + keys
Air Suspension Pump

Then I could strip all ancilleries off the engine to get as much as possible for those, and then get what I can for the engine.

From looking at prices on ebay I should be able to cover my costs with those parts alone but at the cost of the time involved in stripping it.