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Matt
Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 22243
Experience:  BEng hons Mech engineering, in auto industry 22 years
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VW Polo GTI 51 reg. excessive oil consumption

Resolved Question:

Son's car, VW Polo GTI 51 reg. Recently had cam belt change, but garage failed to correctly attach lower pulley. 300 miles later it came off with resultant, to be expected damage. Garage admitted error, removed head and replaced valves. Another 300 miles on and it had used 1.5/2.0 litres of oil. Returned car, head was stripped, new valve guides and seals fitted, seats machined and reassembled (using same valves). 400 more miles and it's used another 2.5 litres of oil (in two top-ups). Prior to cam belt change, oil consumption had been about half litre in 10 000 miles - quite acceptable for 100 000 mile car.
I will return the car yet again, but the problem I now have is that I feel the garage will start quibbling and will no longer accept responsibility for the excessive oil consumption - have changed valves and changed guides (though not at same time) so nothing else we can do.....
The old guides were pretty mashed on the ends and we're distinctly oval - could this have scored/damaged the new valves?
Any ideas what could have happened post cam belt change and subsequent damage? All was fine prior and I just want things back as they were.
Additional info: had gearbox-out repair at same time as cam belt replacement. Thought this irrelevant, but have done some further reading and am wondering if it's possible that the PCV valve could have been damaged during removal/refitting. The power steering reservoir was damaged and required replacement, so feel there was an element of ham-fistedness going on.
Many thanks, ***** ***** for any advice.
Steve
Submitted: 2 years ago.
Category: Car
Expert:  Matt replied 2 years ago.
Hello

I'd agree that the crankcase pressure relief valve (PCV) could do with looking at, these are sprung loaded and are only meant to 'burp' excess pressure every now and then. The exiting gas is piped back to the inlet , however should the valve stick open then the engine tends to suck the air out of the crankcase all the time and this carrys oil over with it.

If you remove the air intake pipe and look inside where the crankcase breather is plumbed in you may find evidence of oil.

If you do find oil replace the valve

another possibility is the new valves have been scratched by the old damaged guides

( as you probably suspect )

in which case they will need replacing again
Customer: replied 2 years ago.

Many thanks Matt

Just means I now must argue the toss with the garage ☹ but at least my opinion has the backing of an expert.

Very grateful for your input - have a good New Year

Steve

Expert:  Matt replied 2 years ago.
No problem Steve
happy new year to you too

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