Porsche 986 Engine failure (potentially head gasket?)
Discussion
Hey all,
I am hoping you can help?
I have a 2003 986 and the head gasket potentially has gone, loads of black smoke out the back, rattling noise at low revs and the oil level has dropped a lot.
Does anyone have any recommendations as to how best to move ahead with this... maybe a recommendation of a good Porsche Specialist in the Hampshire/Berkshire/Surrey area to check the pots? A quick phone call has revealed that a new engine is 7K, as much as the value of the car. Am keen not to scrap the car so any advice/thoughts would be appreciated...
Gary G
I am hoping you can help?
I have a 2003 986 and the head gasket potentially has gone, loads of black smoke out the back, rattling noise at low revs and the oil level has dropped a lot.
Does anyone have any recommendations as to how best to move ahead with this... maybe a recommendation of a good Porsche Specialist in the Hampshire/Berkshire/Surrey area to check the pots? A quick phone call has revealed that a new engine is 7K, as much as the value of the car. Am keen not to scrap the car so any advice/thoughts would be appreciated...
Gary G
Gary Garnett said:
Hey all,
I am hoping you can help?
I have a 2003 986 and the head gasket potentially has gone, loads of black smoke out the back, rattling noise at low revs and the oil level has dropped a lot.
Does anyone have any recommendations as to how best to move ahead with this... maybe a recommendation of a good Porsche Specialist in the Hampshire/Berkshire/Surrey area to check the pots? A quick phone call has revealed that a new engine is 7K, as much as the value of the car. Am keen not to scrap the car so any advice/thoughts would be appreciated...
Gary G
You must stop running the engine. Period.I am hoping you can help?
I have a 2003 986 and the head gasket potentially has gone, loads of black smoke out the back, rattling noise at low revs and the oil level has dropped a lot.
Does anyone have any recommendations as to how best to move ahead with this... maybe a recommendation of a good Porsche Specialist in the Hampshire/Berkshire/Surrey area to check the pots? A quick phone call has revealed that a new engine is 7K, as much as the value of the car. Am keen not to scrap the car so any advice/thoughts would be appreciated...
Gary G
No specific recommendations for where to take car.
In general terms you need to select a shop that is qualified and has the rep to do whatever it takes and you are willing to do to resurrect the engine. This can range from say replacing a head gasket (though I do not think the head gasket is gone) to a full rebuild, or perhaps even drop in a replacement engine.
The way to move ahead is to get the problem identified. IOWs, what is wrong. Knowing this then the shop can advise you as to what is required and can give you an estimate, alternatives -- say a replacement engine if the current engine's problems have rendered it unrepairable (just sayin') -- so you can take a step back and weigh alternatives and make the right decision for you.
Avoid trying to rush the process. You are facing some potentially big bills and you want to make sure you make the right decision.
The rattly noise and black smoke doesn't read like a head gasket failure. The oil level drop may be a red herring. When these engines are run for a short time then shut off the oil level reads low as a lot of oil remains in the engine.
It reads more like a leaking injector. But the shop you select should be able to diagnose whatever it is.
mollytherocker said:
Yep, sounds like scored bores.
Unlikely - having been there (and had new engine) scored bores are normally silent. You do get extra smoke but not loads, and oil consumption is very heavy but levels don't plummet. Desn't sound good though, and +1 to Hartech as best port of call.Good luck. Gutting.
Edited by drmark on Saturday 26th October 19:31
drmark said:
mollytherocker said:
Yep, sounds like scored bores.
Unlikely - having been there (and had new engine) scored bores are normally silent. You do get extra smoke but not loads, and oil consumption is very heavy but levels don't plummet. Desn't sound good though, and +1 to Hartech as best port of call.Good luck. Gutting.
Edited by drmark on Saturday 26th October 19:31
mollytherocker said:
I am pretty sure Baz said that the pistons eventually slap against the walls causing a tapping sound.
In extremis possibly but I had mine for over 8000 miles (it took OPC that long to find the issue) and sounded completely normal. That's why so many people talk about scoping engines - only signs are normally XS oil consumption (1 - 2 litres / 1000 miles, blue (not black) smoke on start up, and sooty tail pipe on opposite side to affected bank (exhaust crosses over). That's why it is so easy to buy a pup.Caveat Emptor
mollytherocker said:
I am pretty sure Baz said that the pistons eventually slap against the walls causing a tapping sound.
As a 996 owner recovering from borescore, I can confirm that the resulting piston slap does knock like b'stard. I can also confirm that Hartech have done a fantastic job restoring my pride and joy
Gary Garnett said:
Hi all,
Big virtual HIGH FIVE and THANKS to all your input/suggestions/thoughts. The car has been transported to Northway's near Reading for some diagnostics, if you are interested and it helps others, I can post what the issue is and what the outcomes are...?
Thanks Gary
Big virtual HIGH FIVE and THANKS to all your input/suggestions/thoughts. The car has been transported to Northway's near Reading for some diagnostics, if you are interested and it helps others, I can post what the issue is and what the outcomes are...?
Thanks Gary
Please do - and good luck
Gary Garnett said:
Hey all,
Well I got a call from Northway's and the car is fixed! A new Oil Regulator at a cost of £250 did the trick. Not sure if there is any lasting damage to the exhaust having put a litre of oil through it so fingers crossed...
Once again guys, thanks for your support
Gary G
Did you mean this component failure?Well I got a call from Northway's and the car is fixed! A new Oil Regulator at a cost of £250 did the trick. Not sure if there is any lasting damage to the exhaust having put a litre of oil through it so fingers crossed...
Once again guys, thanks for your support
Gary G
"The engine air-oil separator is an emissions device located on the top right rear corner of the engine. The separator is responsible for collecting residual gases and vapors contained inside the crankcase and funneling them back into the intake manifold where they can be burned in the combustion chamber. This reduces the overall emissions of the engine."
"When the separator fails, you will begin to see a large increase in the overall vacuum in the engine crankcase. In the most extreme cases, the air-oil separator fails to separate the oil from the air, and oil is then sucked into the intake manifold. Oil in the intake system is not healthy for the engine and it can foul spark plugs and destroy catalytic converters at the very least. The failure of the air-oil separator is often (but not always) accompanied by huge amounts of white smoke exiting the vehicle's exhaust and a generally poor running engine. You may experience a check engine light (CEL) as the oil being drawn into the intake can affect the mixture level. The oil cap may be very difficult to remove when the engine is running due to high vacuum levels. In addition, you may hear a high-pitched squeal from the engine when it's running: this is caused by air being sucked in past the crankcase seal due to the extreme vacuum inside the case."
The air/oil separator has a connection directly into the sump to allow oil to drip back down after being separated from the air mist in the engine. It has a diaphragm that under vacuum seals the top of the engine from the sump and closes the flow path.
When an engine is running fast there is very little inlet vacuum but it is at a maximum when the throttle is closed.
The highest vacuum occurs on tickover and if the diaphragm has become perforated it stops working and allows the oil in the sump to be sucked up into the air intake manifolds and into the engine to burn with the fuel and air.
This creates a lot of smoke and oil in the exhaust. If too much oil is sucked up it can go into the engine and hydraulic lock a cylinder and piston at TDC - damaging them or the con-rod or crankshaft.
It does not usually result in a mechanical noise - just a whistle (from the hole in the diaphragm) however if spark plugs become clogged the uneven running can result in uneven tickover making chains and tensioners clatter.
You cannot see if a diaphragm is perished without cutting the plastic housing open (and then cannot use it again if it was actually OK).
We offer to fit them new as standard to engine rebuilds as it is not worth risking the consequences for the low cost of the actual component.
Baz
When an engine is running fast there is very little inlet vacuum but it is at a maximum when the throttle is closed.
The highest vacuum occurs on tickover and if the diaphragm has become perforated it stops working and allows the oil in the sump to be sucked up into the air intake manifolds and into the engine to burn with the fuel and air.
This creates a lot of smoke and oil in the exhaust. If too much oil is sucked up it can go into the engine and hydraulic lock a cylinder and piston at TDC - damaging them or the con-rod or crankshaft.
It does not usually result in a mechanical noise - just a whistle (from the hole in the diaphragm) however if spark plugs become clogged the uneven running can result in uneven tickover making chains and tensioners clatter.
You cannot see if a diaphragm is perished without cutting the plastic housing open (and then cannot use it again if it was actually OK).
We offer to fit them new as standard to engine rebuilds as it is not worth risking the consequences for the low cost of the actual component.
Baz
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