lower timing chain guide question:

[Unavita]

I need help to a question I can not seem to find the answer for:
My upper guides are pristine. It was after another problem when I had to pull the oil pump that I saw the lower guide is discolored.

My question is:
Is this guide not a part of normal maintenance? Meaning should it have been changed with the uppers?

AND is this a job that would be made easier by leaving the pump off until the job is complete?

Thank you in advance.

 

[gsxr]

Can you post a photo of the guide you are referring to?

 

[Unavita]

yep- give me a minute

 

[gerryvz]

Can you state what you mean by "discolored"? The M119 guides (at least, the three upper ones) are a dark brown color. You can see one of my guides in the photo below, next to a new one. This is with 142K miles on it.







I think it's difficult on the M119 to tell if a guide rail is discolored, unlike the M117, where the rails are a white color and turn very dark brown .... an obvious "discolor."

 

[Unavita]

Thanks for your patients: 9 cars, 2 kids 5 and 3 and 1 happy wife- keeps me busy....

 

[gerryvz]

Doesn't look that discolored to me.

 

[JC220]

Thanks for your patients: 9 cars, 2 kids 5 and 3 and 1 happy wife- keeps me busy....

Whilst new ones are white (I just renewed all timing parts a few months back since I was refreshing a used motor), the original oil pump chain tensioner may well have been that colour from factory. Aka made from the brown plastic.

You only need to worry of you see broken plastic guides or the engine is very high mileage with no records of timing work - really that particular tensioner has very low to zero failure rate.

 

[Unavita]

Thank you both! It is a low mileage engine. 46k km. Additionally the chain looks new as does all the supporting cast.
Still figuring out the metal bit in the pump that cause it to fail. Master ASE (Toyota/ Lexus mech- aka- my brother) informed me the metal bits is a valve keeper. I wrote about this in another post. I am still sourcing the proper tools that the manual calls for.

Thanks all.

 

[JC220]

Thank you both! It is a low mileage engine. 46k km. Additionally the chain looks new as does all the supporting cast.
Still figuring out the metal bit in the pump that cause it to fail. Master ASE (Toyota/ Lexus mech- aka- my brother) informed me the metal bits is a valve keeper. I wrote about this in another post. I am still sourcing the proper tools that the manual calls for.

Thanks all.

Sorry I don't quite follow. Metal part IN Oil pump? Firstly did something happen to this engine you speak of?

Secondly there is a wire screen mesh on the m119 pickup tube and I cant see how metal could get past that.... dont follow the suggestion about valve collet either this sounds like severe engine damage if I understand you correctly but perhaps I'm picking this last post up all wrong!

 

[Unavita]

A supposed valve keeper blew through that screen, got in the gear wheels causing them to be severely damaged and a quick loss of oil pressure. This all happened in seconds. The cause is still under investigation i.e., removing valve train etc. to inspect each valve. If all the keepers are still there and the valves are in tact then the object came from some place else.

 

[JC220]

A supposed valve keeper blew through that screen, got in the gear wheels causing them to be severely damaged and a quick loss of oil pressure. This all happened in seconds. The cause is still under investigation i.e., removing valve train etc. to inspect each valve. If all the keepers are still there and the valves are in tact then the object came from some place else.

That's not good sorry to hear that.

Was there any oil spilled external to the block?

If you can pull the plugs check for mechanical damage first then put a scope down. A dropped valve will be very obvious of course. If nothing seen visually right off the hop then a leak down test would be next IMO and / or in the 124 chassis you can drop the front sump pan easily.

 

[JCM1]

A supposed valve keeper blew through that screen, got in the gear wheels causing them to be severely damaged and a quick loss of oil pressure. This all happened in seconds. The cause is still under investigation i.e., removing valve train etc. to inspect each valve. If all the keepers are still there and the valves are in tact then the object came from some place else.

I recently did a complete rebuild of the oil pump as pressure initially pegged until the motor warmed up. At gentle throttle the pressure would remain constant but only about 1/2 of gauge and upon more aggressive throttle would drop. Upon removal of the oil pan the remnants of the upper timing chain guides were found as per the picture. What was happening, I think, was the chain guide bits were sucked into the oil pump pick up tube screen causing the oil pump to cavitate. that screen is very stout and it would be hard to get anything past it.



The oil pump was rebuilt as well and the upper guides replaced (lower guides were fine - 159,000 km) now all is good.

All the best,


Joe

 

[Unavita]

That's not good sorry to hear that.

Was there any oil spilled external to the block?

If you can pull the plugs check for mechanical damage first then put a scope down. A dropped valve will be very obvious of course. If nothing seen visually right off the hop then a leak down test would be next IMO and / or in the 124 chassis you can drop the front sump pan easily.

I did not see oil and have not scoped it yet. That actually did not come to my mind. I also did not think of a leak down test but also a damn good idea. Thank you! Now to buy a borescope.