Porsche 911 Carrera 4

One of my customers came into the workshop late one Saturday morning to say his 911 had "broken down" in the middle of the MOT test, and the garage reported huge clouds of smoke and engine failure. It is a very tidy Carrera 4 3.6, and his pride and joy. He was utterly dismayed. I told him not to let anyone touch it and get the RAC to bring it in. It duly arrived on the Monday morning and I put the rear up on axle stands.

The underside was wet with oil everywhere and the engine was hydraulically locked; would only turn a few degrees in either direction. This model has twin plug heads: six of the plugs being accessible from the engine bay, the other six from underneath. The only two you can remove without removing anything else are the two right hand rears. They came out soaked in engine oil and when I stood back there was a pool forming on the floor running out of the plug apertures!! On removing the others this was the result :-

Every cylinder filled with engine oil. But it doesn't end there because you have to find out how the hell the oil got there. This is what I found in the inlet manifold and plenum chambers:-

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Then there was the exhaust. This is the main silencer stood on its end to drain :-

I then had to strip, degrease and clean virtually every part of the intake and exhaust systems, renew the plugs and filters and change the oil.

This is what happened.

For those of you not familiar with the 911, it is an air coooled engine that is dry sumped and has a catch tank in the offside rear wing. To properly check the engine oil level you have to have the car fully warmed up until the oil thermostat opens allowing the system to fully circulate and then dip the tank with the engine idling. If you check it with the engine switched off and cool, you will get no reading on the stick. You may be starting to get the picture.

Before carrying out an emissions check the tester is obliged to check the oil level. Guess who thought the engine was empty?

The close circuit breathing system on this engine has two large breather hoses going into the top of the tank. They overfilled it so much that the vacuum created in the hoses cause the engine to suck oil from the tank and pump it straight into the intake system and into the cylinders. The engine smoked like hell and then eventually hydraulically locked.

After the clean up operation I got it fired up and took it for a jaunt, still smoking quite badly for the first few miles, but finally clearing. A couple of cans of injector cleaner and some oil additive and she was purring like a kitten.

Incredibly, no engine damage, but my god what a time consuming job.

One relieved customer and a nice engine bay once again.

The finale to this was quite agreeable to all. The tester agreed to pay for a substantial portion of the bill; I think he is being philisophical and putting it down to experience.

This customer is a real gent actually, and the reason he did not push the issue of full payment is because the act of stripping all the ancillaries and the exhaust and refitting everything, including setting up, has resulted in the car running like a scalded cat, so he's quite chuffed about this and had no objection to part payment. He also had no desire to see the tester lose his job and MOT licence. I can guarantee he won't make the same mistake twice!!

Still, all's well that ends well.