02 Tacoma 4cyl, Penzoil 5w-30, 903 miles on oil

Messages
64
Location
Roanoke, VA
the reason this was sampled with only 903 miles on the oil is that the engine was knocking when cold and accelorating from a stop and the owner, a mechanic, could not pinpoint the cause. once the engine is warm the knocking goes away... i am not at all familiar with this engine, but 40ppm Fe after only 903 miles of use seems very high to me. also, the oil viscosity has sheared down to a 20 weight. any insights, thoughts would be greatly appreciated.
 
Messages
723
Location
Lower Alabama
All the wear numbers seem high. 40 ppm Fe at 1000 miles is a problem. As is 9 ppm Cu and 13 ppm Si. Check your intake system for leaks. I'm guessing you're getting dirt in your engine and it's basically acting like sandpaper.
 

SUNRG

Thread starter
Messages
64
Location
Roanoke, VA
thanks for the feedback. do you think the knocking when accelorating after a cold start could possibly be resolved by fixing an air intake leak? i will definitely have him thoroughly examine the air intake system. thanks again and any additional feedback / theories / analyses would be great. cheers
 
Messages
22,188
Location
Colorado Springs
When you say knocking, is it more of a rythmic knock or a tick? If it's more a tick, then it's likely just valve lash. If it's an honest to goodness knock, then that may not be good. Could also be piston slap; Toyotas are not immune to it (like mine). What oil filter do you use? Oil filters have been known to cause startup/cold knock.
 

SUNRG

Thread starter
Messages
64
Location
Roanoke, VA
Quote:
When you say knocking, is it more of a rythmic knock or a tick? If it's more a tick, then it's likely just valve lash. If it's an honest to goodness knock, then that may not be good. Could also be piston slap; Toyotas are not immune to it (like mine). What oil filter do you use? Oil filters have been known to cause startup/cold knock.
thanks for the post. i'm not the owner - it's actually my father in-law's truck. i'm going to ask him today whether it's a tick or a full-on knock and what oil filter he's using - and i'll post that info hopefully later today. cheers
 

SUNRG

Thread starter
Messages
64
Location
Roanoke, VA
the oil and air filters were OEM Toyota. yesterday i purchased Mobil 1 5w-30, a Mobil 1 oil filter and a Purolator air filter - and it all should be going in today after a very thorough air intake system inspection. i'll report back as to whether any air system leaks or air filter issues were apparent. i hope the M1 will be less likely to shear to a 20 weight than the Penzoil 5w-30 (8.9cSt after only 903 miles). cheers!
 
Messages
5,785
Location
Dixie
Did this analysis show any nickel at all? That would indicate abrasive wear of the intake valves, which are composed of stainless steel. I owned the '95 version of this truck for nine years and tested the oil in it 5-6 times. Iron wear should run about 2 ppm/1000 miles, so if this 40 ppm is correct, it's very high. These engines are known for leaching silicon(e) from the seals/gaskets. Since you only have 35k total miles on this engine, that could be a big part of the Si you're seeing here. I had excellent result with the OEM air filter, so I doubt that's the issue. The 40 ppm of Iron could be a typo...I'd test the Mobil 1 after a few thousand miles and see how that does.
 

SUNRG

Thread starter
Messages
64
Location
Roanoke, VA
Quote:
Did this analysis show any nickel at all?
unfortunately this CAT lab does not test for Ni... the air intake and the OEM air filter all appeared to be in great shape. the OEM air filter was replaced with a new Purolator. new oil and filter should go in soon. i will pull a sample in another 1000 miles to see how the M1 oil and filter are doing. thanks for all the posts and if we learn what the cause of the knocking is i'll post it. cheers
 
Messages
9,448
Location
USA
I have never heard a Toyota with piston slap but that does not mean it can not happen. I think that it would be more likely that he has either a worn thrust washer/shim or it is missing. THe only thing is it would not go away it would stay present. WHat is up with all of the "P" did this enigne have a coolant leak at some point? I ask becasue if he has a blown head gasket it can sometimes make a knocking noise until the parts expand and seal it up. The knocking noise is usualy from steam.
 
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