[Andy L]

I have 89k on this vehicle and lately I've notice a tick that increases in speed as I rev the engine. It's only been happening for the last 500 miles or so. I can live with this but I've also developed a skip in cylinder #5 along with a check engine light, which confirms #5. I tried a number of items swapping coils, plugs etc. with no changes. I brought it to my mechanic and could only confirm the things it was not - coil, plugs, injector. The compression test was fine. He also took off the valve cover with nothing new discovered, including running the vehicle for a short time. His best guess is that it is the lifters (as most people determine) with the possibility it could have damaged the cam. To rebuild is thousands of dollars but I am not convinced this is the real cause. I then decided to have him add Seafoam additive. It seems to have improved this situation but by no means resolved it.
In park, at idle, the engine runs fairly smooth, better after it warms up. When I put it into gear the skip is very noticeable. Once I give it gas on the road, it runs great. in general as the car warms up it runs better.
After reading a number of threads on this forum, there are a few items I will investigate - new PCV valve (cheap and easy), and look into "the problem turned out to be the sonic welds on the composite intake manifold and a collapsing vacuum hose to the PCV valve. Apparently the manifolds go bad over time and then need to be repaired or replaced."

So my questions to the audience are 1) has anybody looked into this solution as a viable answer? 2) are there any other suggestions as to the cause and repair for my issue?

Thanks

 

[MRBOXER]

I have 89k on this vehicle and lately I've notice a tick that increases in speed as I rev the engine. It's only been happening for the last 500 miles or so. I can live with this but I've also developed a skip in cylinder #5 along with a check engine light, which confirms #5. I tried a number of items swapping coils, plugs etc. with no changes. I brought it to my mechanic and could only confirm the things it was not - coil, plugs, injector. The compression test was fine. He also took off the valve cover with nothing new discovered, including running the vehicle for a short time. His best guess is that it is the lifters (as most people determine) with the possibility it could have damaged the cam. To rebuild is thousands of dollars but I am not convinced this is the real cause. I then decided to have him add Seafoam additive. It seems to have improved this situation but by no means resolved it.
In park, at idle, the engine runs fairly smooth, better after it warms up. When I put it into gear the skip is very noticeable. Once I give it gas on the road, it runs great. in general as the car warms up it runs better.
After reading a number of threads on this forum, there are a few items I will investigate - new PCV valve (cheap and easy), and look into "the problem turned out to be the sonic welds on the composite intake manifold and a collapsing vacuum hose to the PCV valve. Apparently the manifolds go bad over time and then need to be repaired or replaced."

So my questions to the audience are 1) has anybody looked into this solution as a viable answer? 2) are there any other suggestions as to the cause and repair for my issue?

Thanks

misfire can be also one of your enjectors

 

[Andy L]

misfire can be also one of your enjectors

thanks for input but it did not work. I'm awaiting a PCV valve and hose. Not likely but I will try.
Next step is to check the manifold and gasket for leaks using brake cleaner.

 

[DGO]

Have you checked for any codes? If you don't have a code reader remember you can try the keydance

 

[Andy L]

I have. I believe it was 305 showing misfire on the cylinder #5

 

[CtCarl]

I did have a very light tick in my 5.7 that turned out to be the PCV valve. The way I diagnosed it was simply by applying pressure manually to the top of the valve, the sound would stop instantly.

I tried cleaning it but it made no difference. A new replacement cleared it up.