Help. power loss at about 4000rpm

[Guest]

I'm after some help regarding my '86 944 turbo.

While driving yesterday I changed down a gear to overtake and was greeted with a cloud of black smoke and a complete loss of power at around 4000rpm.

Fearing the worst I quickly applied the clutch and coasted to a stop. The engine sounded fine and rev'ed without any problem. I checked the water, oil etc and when everything looked fine I started for home. Now if I floor it the boost goes to about 1.3 and at about 4000rpm the engine starts to splutter. It's fine as long as I'm not wearing my lead boots.

Alan.

 

[944Turbo]

Have you got a boost enhancer? This is classic overboost protection symptoms if you switch the ignition off and on again (or others say after 30 secs ish) full boost should be returned.
I and others have found at this time of year the cold dense air will allow the overboost protection to cut in (particularly in 3rd or 4th), if you have a boost enhancer slackening it off one turn will cure it till the warmer weather returns if not then it could be a leaky vacuum pipe or sticky wastegate.
Tony

 

[Guest]

Sounds more like a boost leak to me chaps. When you say boost at 1.3, do you mean on the dash gauge? If so then you really have only 0.3 bar gauge pressure. The black smoke and spluttering is because your turbo is drawing air through the AFM that is telling the ECU to supply the appropriate amount of fuel. If some of the air is leaking out then the motor will run very rich as a result. Check hoses on intercooler, turbo pipework, dump valve etc.

 

[Guest]

I have now found out what the problem is.

I went to check the vacuum pipes etc for leaks on Saturday, and found that the expansion tank was empty. I checked the oil cap and it looks like a custard factory. I fear the head gasket has gone. As you can imagine I am not happy as I bought the car last year and have done less than 3000 miles. Reads 69000 ish. Can anyone recommend a garage in or around Bristol.

Thanks for the help so far

Alan.

 

[937carrera]

Rob Morley at Porschetech is in your area I believe, sorry to hear about the custard, and hope you don't find any rhubarb []

 

[Fen]

I think it's as much an age thing as a mileage thing when the head gasket goes. When mine went it was different symptoms (3 cylinder startup in the morning, appetite for a bit of water, white exhaust when cold), but that was at 149k.

 

[RSGulp]

ORIGINAL: gadgetsmaster

Can anyone recommend a garage in or around Bristol.

Can anyone recommend a garage in or around Bristol.

Alan,

I can recommend Brian Woodward at Woodward Motors in Rockhampton off junction 14 of the M5. His number is 01454 261067. See ad in Porsche 911 World or PCGB Porsche Post.

He has looked after my 911 for the last four years and is always very meticulous about doing any job correctly. He also has very reasonable rates - probably due to low overheads as he's not based in a city centre.

Obviously you don't get the 'vip service' that you'd get at an OPC but they've got a kettle and sometimes a biscuit and a great interest and knowledge of all 'older' models of Porsche. Whenever I'm in there they always have a wide selection of Porsche's being worked on from 944s, 911s through to 964s etc.

Rich Claridge