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Greg
Greg, Shop Owner
Category: UK Car
Satisfied Customers: 6808
Experience:  17 years Shop Owner /Technician. 27 years experience,
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My car pings and has a slight misfire under 4000 revs once

Customer Question

My car pings and has a slight misfire under 4000 revs once reach 4000 revs it is fine what can be the problem it is a Vw sharan 1.8 t
Submitted: 9 months ago.
Category: UK Car
Expert:  Greg replied 9 months ago.

Is the chec k engine light "ON" when the engine is running .

What fuel are you using .

Any work been done on the engine .

When was the last engine tune up done .

Rgds Greg

Customer: replied 9 months ago.
The is no lights burning and the engine was tuned 3 months ago and I use 95 unleaded
Thanks
Tony
Expert:  Greg replied 9 months ago.

Okay good thank you .

If you have a good tuned engine ,correct fuel ,then check for malfunction codes as this will most likely be your knock sensor that has failed ,Now this sensor will not flag a check engine light, BUT will store the knock sensor code P0325 .

Have this checked and if this code is present replace the knock sensor .

This Knock sensors senses when the engine starts to knock (ping) and adjust the timing .

hence the bad running engine .

If the sensor fails the timing can not be adjusted and will continue to ping...

If no pinging .

Then check the fuel pressure,

Check the MAF sensor ,a common issue for the type of problem you have.

In some cases the MAF just needs cleaning with carb/throttle cleaner spray .

If all is good then let me know,

Can you get the use of the scan tool with live data if needed.

Still need additional information then please get back to me with the reply button, and not the poor or bad service, this way i can get back to you or suggest another expert if needed.

Your deposit does not pay me until the answer is rated in a positive way,
A bad rating does not constitute a refund.

If you are not happy or you have sorted out your problem before the answer then please let me know with the reply button .

Kind regards Greg.

Customer: replied 9 months ago.
Hi Greg I think I am going to remove the Cylinderhead and see if the gasket is not blown between cylinders
Thanks
Tony
Expert:  Greg replied 9 months ago.

Do a cylinder compression test .

Co2 coolant test this will confirm cylinder head gaskets .

Both negative and prove good do a cylinder leak down test .

Greg

Customer: replied 9 months ago.
Ok will do that it is just that I don't have time to do this
Expert:  Greg replied 9 months ago.

Best to do the test to confirm the cylinder head gasket .

You may have a good gasket still and changing it maybe a waste of good cash ?

Rgds Greg