Hello, folks.
You can probably infer from my log in name that I have a box full of fractional tools. However, my metric collection is rapidly growing with relatives and newer cars sharing my attention.
The immediate issue is my daughter's Infiniti with the M45 engine. It started the other morning with a very loud clanging sound. It sounded about half engine speed and my knee-jerk reaction was a collapsed lifter. I then thought for a while and to my understanding a DOHC engine shouldn't have lifters. Since the noise was quite scary, it was flat-bedded to the dealer. The dealer also said it was a lifter, but my daughter said her dad didn't think DOHC engines had them. The dealer said they have an analogous part; that is the thrust of the topic title. Is his statement true?
Related question: can I download (somewhere) an exploded and annotated drawing of the M45? Or, failing that, technical drawings of the valve train?
Any help would be appreciated.
T-BIRDMAN
Does the M45 eng. have an equivalent to hydraulic lifters? (eg: lash eliminator)
Re: Does the M45 eng. have an equivalent to hydraulic lifters? (T-BIRDMAN)
Yes, the VK45 (and VH engines for that matter) have lifters.
The valve train on the VK45 is not a direct acting, cam-on-bucket type, but rather it has a small rocker that sits between the valve and the camshaft. To adjust valve lash, on the other end where the valve is anchored, is a small HLA or hydraulic lash adjuster on which the lash is automatically adjusted and the force of the camshaft is applied to when the valve is open. Periodically the seals or valving will blow and the HLA will no longer hold oil, collapsing the adjuster, and causing the ticking sound.
Below, some pictures of a VH45 head (the cousin of your daughter's VK) that were here on nico club. You can see the rocker arrangement below the cam as well as the lifter in the head.
The valve train on the VK45 is not a direct acting, cam-on-bucket type, but rather it has a small rocker that sits between the valve and the camshaft. To adjust valve lash, on the other end where the valve is anchored, is a small HLA or hydraulic lash adjuster on which the lash is automatically adjusted and the force of the camshaft is applied to when the valve is open. Periodically the seals or valving will blow and the HLA will no longer hold oil, collapsing the adjuster, and causing the ticking sound.
Below, some pictures of a VH45 head (the cousin of your daughter's VK) that were here on nico club. You can see the rocker arrangement below the cam as well as the lifter in the head.
Re: Does the M45 eng. have an equivalent to hydraulic lifters? (ravera)
Ravera:
I just want to thank you for your complete and understandable response.Perhaps, if I had the stones the dealer had, I would have run the motor longer, like 5-8 minutes, but I was concerned about knocking pieces around the engine.
They ran it and eventually the noise stopped and the engine is now running fine. Seems as though the old ploy of blaming foreign particles may be right, at least in this instance.
The oil and filter was changed so we will see if the noise was a chance encounter, a deteriorating seal, or something stuck somewhere. Engines are arbitrary as to where they stop when turned off. I believe, if there is a fault in an HLA, that it would be sensitive to that component's position at turnoff, eg, valve at full open position or on the base diameter.
Thanks again.
I just want to thank you for your complete and understandable response.Perhaps, if I had the stones the dealer had, I would have run the motor longer, like 5-8 minutes, but I was concerned about knocking pieces around the engine.
They ran it and eventually the noise stopped and the engine is now running fine. Seems as though the old ploy of blaming foreign particles may be right, at least in this instance.
The oil and filter was changed so we will see if the noise was a chance encounter, a deteriorating seal, or something stuck somewhere. Engines are arbitrary as to where they stop when turned off. I believe, if there is a fault in an HLA, that it would be sensitive to that component's position at turnoff, eg, valve at full open position or on the base diameter.
Thanks again.