Toyota 2ZZ-GE intake cam wear - bad oil or bad filter?
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Just wanted to post a quick update and lessons learned.
I have replaced the intake camshaft and the 4 rockers. The flat-tappets on the rockers were badly worn as I expected based on how wiped the camshaft was. The rollers were OK. Valve lash was in fact out of spec (too tight). I re-shimmed it to spec. The car is now back on the road, runs smooth.
Having done extensive research on the topic, I place 90% of the blame on the government for needlessly regulating out ZDDP from motor oil formulations and 10% of the blame on the out-of-spec valve lash. Some of you commented on my oil change interval. The only 2 times I exceeded 9,000 miles was when I was driving round-trips from NY to TX. Easy miles, not using lift. Oil change intervals were not a factor here.
Going forward I will be mixing in a quart of Valvoline VR-1 (high zinc formulation) at every oil change, as well as 3oz of Rislone ZDDP additive. Based on my research, the catalytic converter poisoning argument against ZDDP is greatly exaggerated, if not completely false.
Lessons learned: 1) Never trust the government. 2) Modern motor oils (API SM, SN and newer) do not provide adequate protection against wear in high performance, high-revving engines, especially when equipped with flat-tappet camshafts.
Analysis of ZDDP content and thermal decomposition in motor oils
AMSoil engineer explaining importance of ZDDP additives (@13:27)
Old vs New rocker (note the badly worn pad on the left)
New intake camshaft in
All buttoned up
I have replaced the intake camshaft and the 4 rockers. The flat-tappets on the rockers were badly worn as I expected based on how wiped the camshaft was. The rollers were OK. Valve lash was in fact out of spec (too tight). I re-shimmed it to spec. The car is now back on the road, runs smooth.
Having done extensive research on the topic, I place 90% of the blame on the government for needlessly regulating out ZDDP from motor oil formulations and 10% of the blame on the out-of-spec valve lash. Some of you commented on my oil change interval. The only 2 times I exceeded 9,000 miles was when I was driving round-trips from NY to TX. Easy miles, not using lift. Oil change intervals were not a factor here.
Going forward I will be mixing in a quart of Valvoline VR-1 (high zinc formulation) at every oil change, as well as 3oz of Rislone ZDDP additive. Based on my research, the catalytic converter poisoning argument against ZDDP is greatly exaggerated, if not completely false.
Lessons learned: 1) Never trust the government. 2) Modern motor oils (API SM, SN and newer) do not provide adequate protection against wear in high performance, high-revving engines, especially when equipped with flat-tappet camshafts.
Analysis of ZDDP content and thermal decomposition in motor oils
AMSoil engineer explaining importance of ZDDP additives (@13:27)
Old vs New rocker (note the badly worn pad on the left)
New intake camshaft in
All buttoned up
OVERKILL
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Just use a full SAPS Euro oil if you really think it's the oil (the consensus seems to be it's the lash though...). They have higher levels of AW additives.
Tight valves = No Bueno
Nothing to do with the Govt.
Nothing to do with the Govt.
This is one reason I use ACEA A3 oils. If you're not burning oil zddp shouldn't make it to the catalytic converter.
People - me included forget that Toyotas do need valve adjustments. But, the dealer techs rarely do them, and many indie Toyota techs say there really isn’t a need. It’s not a terrible job on most Toyota engines - just time consuming and a certain amount of precision is needed. And special tools to depress the lifter buckets while shims are being swapped.
The dealers don’t keep shims in stock, and some engines(Prius 1NZ-FXE, 3UZ-FE Lexus variant) use shim under bucket or adjusting lifter buckets for valve clearance. Meaning, the cams need to be pulled, which can be a pain on the VVT-i 2UZ/3UZ.
The dealers don’t keep shims in stock, and some engines(Prius 1NZ-FXE, 3UZ-FE Lexus variant) use shim under bucket or adjusting lifter buckets for valve clearance. Meaning, the cams need to be pulled, which can be a pain on the VVT-i 2UZ/3UZ.
Mobil1 0w40 would be the oil I use with 5K OCI and a Wix/Napa Gold filter changed every time.
It´s a Toyota it cant be anything wrong with a part in the car so it has to be the oil
I would blame bad maintanence that not checked valve clearence and adjusted it in time
Technically, this engine is made by Yamaha, sold as Toyota 2ZZ-GE. See attached image of the timing chain cover with the Yamaha logo. All cars break, including Toyotas of course. I replaced many parts on the car over the years but this particular wear issue is something that shouldn't have happened with regular synthetic oil changes.It´s a Toyota it cant be anything wrong with a part in the car so it has to be the oil
I stand by my conclusions. 1-line responses using"lol" as arguments have zero weight.
In all I spent 30+ hours repairing this (including all the related jobs as mentioned) and probably just as much time doing research on the lubrication challenges in high-revving performance engines post the 2004 govt-mandated ZDDP reduction regulation fiasco. High levels of zinc/phosphorus additives used to be common in all synthetic oils before that. So it's hard to blame Yamaha/Toyota. They designed the engine in the late 90's based on the lubricants of the time which all had good levels of ZDDP wear protection.
Many Lotus/Toyota owners with the 2ZZ-GE have found that the intake camshaft wipes even when the valve adjustment is within specs. I doubt 3-4 hundreds of a millimeter would've made a noticeable difference. In lift mode with the high cam profiles engaged, the 2ZZ-GE is simply a high-revving, high-strung princess that needs a lot of wear protection that modern "street use" 5W-30 synthetics sadly cannot provide. The labels on post-2004 passenger car synthetic oils should include a warning: "Not suitable for performance engines with flat-tappets." I had no idea until I found out the hard way.
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How far out of spec? And was every cam lobe that was damaged out of spec?
Spec on the intake is 0.08-0.18 mm. All 4 high-profile cam lobes looked equally wiped to me as did the pads on the rockers. All the low-profile cam lobes were fine with no visible/palpable wear, no wear on the rocker rollers either. After installing the new camshaft, on two cylinders I was able to slide in the 0.04 mm feeler gauge easily but the 0.06 mm was tight. The other two cylinders were below 0.04 mm.
I re-shimmed with 0.16 mm as the target. After reassembly I measured between 0.10 mm and 0.14 mm on all 4.
But did you measure the valve clearance on the old damaged cam before disassembly? Measuring after putting the new cam in tells nothing about what the clearance was on the setup before disassembly.
Partially. With old camshaft:
0.00 mm on #1
0.06 mm on #2
I stopped there because A) #3 and #4 were out of phase and I didn't want to turn the engine out of TDC with the timing chain tensioner out and B) I knew I'd be replacing the camshaft and do new measurements. Of course after I replaced the camshaft I had to turn the engine anyway but at that point the old clearances didn't matter.
In spite of #2 being close to spec the high-profile cam and rocker pad wear was as bad as it was on #1.
I will admit that Honda's VTEC > Toyota (Yamaha) VVTL-i because Honda uses cams on rollers even on the high-profile cams. But then again, Yamaha couldn't have anticipated mandated cuts to zinc additives in oil at the time they designed the rockers.
0.06 mm is only 0.002 inch. Are the valve clearance specs that tight on these engines?
Yes! 0.08-0.18 mm on intake side. Like I said, high-strung princess. But makes 100HP/liter of displacement.
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I don't think it was an oil problem. If it was caused by the oil, then both cams would have shown the same damage because the most force/stress on the metal and oil is when the valve is all the way open (ie, at the highest valve spring pressure). Also, I don't think it was cause by tight valve clearance because even if the valve was open super slightly there isn't much force between the follower and cam. Only way I could see the tight valve clearance contributing is if that caused the cam to actually run at a much higher temperature, causing the oil on it to break down and cause the wear damage - highly unlikely IMO.
If it's actually an "oiling problem", then maybe for some reason that camshaft doesn't get the proper oil flow supply - lack of oil flow is very detrimental. Or that camshaft wasn't heat treated correctly, but the other one was. But I'd say the oil wasn't the issue just because of what I described above.
If it's actually an "oiling problem", then maybe for some reason that camshaft doesn't get the proper oil flow supply - lack of oil flow is very detrimental. Or that camshaft wasn't heat treated correctly, but the other one was. But I'd say the oil wasn't the issue just because of what I described above.
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Lol what? Synthetic oil can prevent issues regarding material/engineering/design/valve adjustment issues?
Darn government!
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