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Matt
Matt, Engineer
Category: VW
Satisfied Customers: 20598
Experience:  Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing
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Volkswagen Westy: Vw westy 2.0. Heats up, loses power and makes

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Vw westy 2.0. Heats up, loses power and makes a clattering noise. If I stopped for five minutes even at idle without shutting the engine down it would run fine for ten minutes and then start the loss of power and clattering again. Any ides?

Hello

1st thing to check is the oil level in the engine and if thats OK then I'd suggest measuring the actual oil pressure with separate mechanical gauge - this can be plumbed into the engine via the current pressure switch port -

If you do have a low pressure reading ( should be 3 bar (44psi) at 2000rpm) then replace the oil pump and ensure that the pump pickup in the sump hasn't come loose or is blocked

Also try removing the auxiliary drive belt and turning every pulley and ancillary ( power steering pump , alternator etc) by hand. All should turn easily (with the exception of the AC pump) with no grittyness or wobbly pulleys- If you do find a sticky pump / alternator then it should be replaced or repaired

If the engine is stone cold you can briefly run it with no belts to see if the noise changes or has gone away, this will help show if an ancillary is the issue

Examine carefully the condition of the bottom / crank pulley as these are composite construction with a rubber element and its possible this rubber is breaking up and allowing the two metal portions to move.

 

Customer: replied 3 years ago.
Thanks Matt.
If the oil pressure is ok what should I look at next? What has me perplexed is that when it gets hot it loses power but when I pull over for just a few minutes even while not shutting down the engine it seems to "fix itself" and runs and sounds great for about ten minutes. When I parked it after limping home i went out the next day expecting the motor to be seized up. It started immediately and sounded great. What happens when the motor overheats to cause it to lose power? Just trying to figure out what to look at next in case the oil pressure is ok. Is there a chance the oil pressure goes down when it gets hot? Could it be a timing issue? Crazy that it starts right up. I appreciate your help. This is a 1981 westy and we love to camp in it. I just want to be able to go farther than my driveway to camp lol.
Hello Monty

if oil pressure is OK then check the ancillaries as I suggest and then I'd check for

a lack of fuel pressure from the electrical pump at the tank.

If the connections to the pump are corroded or damaged then the pump could stop at any time or could not be running at full speed. Check that its relay switches in and out and the relay contacts are clean and bright – replace the relay if in any doubt and do the same for the fuse,

Ideally measure the pressure at the inlet to the carb (should be 2-3 psi) and if this is low check the pump as described and also consider changing the fuel filter as if this partially blocked this too will reduce pressure.

Customer: replied 3 years ago.

Matt, please explain how low fuel pressure would cause the car to lose power but then right itself after parking on the side of the road for five minutes. I checked the ancillaries. I will put an oil pressure device on today. I do not think it is a fuel problem. I changed the pump and filter about a month ago. I will check it but I don't see how this can fix itself by idling on the side of the road. It is as if the motor is heating up at normal speeds and loses power. Once I stop the motor seems to cool a little. Could be the oil but it has about 500 miles on the oil. This is a crazy thing happening and I would like to know if it could be a timing problem. Is there something in the normal operation of the engine that could cause it to overheat?

Hello Monty

if the fuel pressure is low then you'll run OK for a little while and at low load levels but when you try accelerating you'll empty the float chamber in the carb and have no power



so another thing to check if the fuel supply / pressure is OK then remove the top of the carb to see if the fuel level in the float chamber is about 2/3rds of the way up

if its low then tweak the small tab on the back of the float that pushes against the valve into the chamber to adjust the float height
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