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Greg
Greg, Technician
Category: Car
Satisfied Customers: 6803
Experience:  Automotive diagnostic tech
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My Vw passat 1.6 fsi is leaking on two valves on two cylinders.After

Customer Question

My Vw passat 1.6 fsi is leaking on two valves on two cylinders.After bleeding and replacing the hydraulic tappets the car will run fine for a few seconds as the valves "clatter" and refill.
I have fitted new valves, valve seats, head gasket, rings and new hydraulic tappets etc.

Martin
Submitted: 3 years ago.
Category: Car
Expert:  Greg replied 3 years ago.
Hi.

Did you replace the hydraulic tappets with new ones .

Which two cylinders, No.3 and 4,?

What is the compression test ?

Rgds Greg
Customer: replied 3 years ago.

Hi,


The problem is with cylinder 3 and 4. When the car came in I had very low compression on these two cylinders - I replaced the valves and seats


( using a specialist shop). The pressure test is now around 180 psi.


However with the manifold removed and cranking the engine there is a leak through the valve ( exhaust ) in cylinder 3 and inlet in cylinder 4.


I have fitted new hydraulic lifters in these cylinders only. Also when testing the engine oil pressure I have really low pressure - the red light does not show red but the pressure reading is almost negligable.


There is no wear on the cylinders and there does not appear to be any excess movement in big bearings etc .


Regards,


 


martin

Expert:  Greg replied 3 years ago.
Hi .

Martin can you do a leak down test on these two cylinders this will confirm the valves are seated fully .

If the the hydraulic lifters are not getting enough oil pressure then you will have problem with No, 3 and 4, this is why i asked .

You could have on all cylinders good compression and still have bad valve seating this is why its important to have a leakdown test done .

Regards greg
Customer: replied 3 years ago.

Hi Greg


 


This is a VW 1.6 fsi petrol engine. The rocker cover houses the two chain driven cam shafts. With this assembly removed there is no variation in leak down between any cylinder - the leak down is gradual and consistent into the sump.


With the cam shaft assemblly in place(and the lifters bled) the car will start


and run fine for say 30 seconds as the valves clatter waiting fro the lifters to fill. Now gradually the car starts to miss on thse two cylinders to the extent that the car will not idle. Removing the spark from cylinder 3 and 4 makes no difference to the car at this stage.


Regards,


 


Martin

Expert:  Greg replied 3 years ago.

Martin so the ticking valve keep ticking and and don't charge then starts to miss.

If this is the case start engine and rev to 2500rpm for 10 mins this will bleed the hydraulic lifters / tappets . if this does not work then your oil pressure will have to be rechecked.
what is the pressure when the engine is at 3000rpm.

Greg
Customer: replied 3 years ago.

Hi Greg,


When the engine starts the "clattering" sounds as the lifters fill and the car runs on all four for say 30 seconds. Then the "clattering" sound disappears


( as as the lifters fill, I assume) but now the engine starts to gradually miss. This missing becomes worse to the point that the engine now only fires on cylinder 1 and 2.


On checking engine oil pressure I have now found that engine oil pressure is almost non existent - though the red engine oil light does not show.


 


Regards,


 


Martin

Expert:  Greg replied 3 years ago.
Hi martin .

This is your problem this is why 3rd and 4th cylinders drop out first as they are the last in line for oil .
Check the oil pan for dents or pushed in and blocking of the pick up tube,remove pan and check for sludge blocking the pick up tube ,if all is clean replace the oil pump .

Need further assistance with this issue then please get back to me .

Please rate my help a 3 to 5. " If you are not satisfied please don't rate."
We can continue to work or I can opt out .
For further assistance there is no extra charge after accepting .
If I don't reply soon I will as quick as I can as we may be on different time zones

Rgds Greg

Customer: replied 3 years ago.

Hi Greg,


 


Are you saying low oil pressure is my problem?. The lifters are fine until they fill.


I have removed the sump and cleaned out all sludge, have cleaned relief valve, filter and pipe etc and refilled with new oil.


When I tested the oil pressure it was found to be almost non existent.


I thought low oil pressure would prevent the lifters from filling.


When I take out the lifters they are always rock solid.


 


Regards,


 


Martin

Expert:  Greg replied 3 years ago.
Hi Martin .

This is getting strange, but if you have low oil pressure, the oil pressure in the lifters are not high enough to keep them at the needed values ,

You have to do the oil pump whatever, as low oil pressure will result in a damaged engine

Regds Greg.

Customer: replied 3 years ago.

Hi Greg,


 


This is strange. I have worked on all makes of plant and cars for more than thirty years and have never replaced as many parts to no avail.


 


It will take a week or more for me to get the oil pump and get it fitted.


Can I come back to you then or does this become a new question and a new charge then?


 


Regards,


 


Martin

Expert:  Greg replied 3 years ago.
Hi Martin .

No problem come back when you have done this .

If you pay now or later i will be here to assist you and no extra payment needed.to carry on.

Rgards Greg

Customer: replied 3 years ago.

Hi Greg,


Fitted new oil pump and gasket at timing chain side cover. Still have almost no oil pressure. This is a petrol 05 reg VW 1.6 fsi.


Do you have any idea where the oil could be getting lost?


Do you know if there is any type of relief valve built into the oil filter housing?


There is a horizontal hole that seems to lead back into the chain housing from the oil filter housing. Could the oil be getting back into the sump from here.


 


Thanks


Martin

Expert:  Greg replied 3 years ago.
Hi .

Martin please let me know which oil filter you are vusing and its part Number .

Greg

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