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Valve Adjustment, AGAIN
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Sorry to pester y'all about V6 valve adjustments, but here goes. The 1993 Warrior has 100K miles on it, and I doubt anyone has ever looked at the valves. My local old mechanic said they "sounded fine," the rig runs great, and to leave them alone. However, someone on Facebook (!) said that you couldn't hear the valves on these campers go bad, and to check the compression.
I have a new mechanic and sent the camper to him yesterday, to see if he could figure out why the check engine light was on (old mechanic couldn't, said to put tape across it -- as did everyone in my family -- but that bugs me). I added a note to the keys at the drop box asking if he could check the compression. Assuming the compression is still good, should the valves be "adjusted?" I love the camper and am trying to be proactive -- put a new V6 engine in my 2002 Toyota 4Runner and it was a little over $6K and took nearly 5 months! Thanks, Sue Crowe Talking Rock GA |
开云体育It may be difficult to find a mechanic in rural Georgiathat is experienced with 30 year old Toyota engines.? If you want to be pro-active, have the valve clearances measured? manually by removing the two valve covers to gain access to the mechanical valve lifters. Especially check the six exhaust valve clearances. ? I guess you’ll just have to call around different shops and ask if they have anyone experienced and willing to measure the clearances on a 30 year old Toyota 3VZ-E V6 overhead cam engine. Or if you can’t find anyone, call around and ask if they have anyone that can do a cylinder compression test on a 30 year old Toyota 3VZ-E V6 overhead cam engine. If compression is high and even (around 170-190 psi) on all six cylinders then you can be pretty certain the motor can be driven another 15,000 - 30,000 miles without adjusting clearances. But if some cylinders are trending lower psi, then it’s important to get the exhaust valve clearances on the affected cylinders? loosened?up by installing a thinner valve adjusting metal shim. Here is a long video about checking and adjusting valve clearances on a 24 valve version of your Toyhome V6 - in fact - it's the same 5VZ-FE engine that’s in your 2002 4Runner. ?At the 1:10 mark they talk about how the cylinder compression was restored on cylinders that had their valve clearances adjusted. ? Paul Cherubini
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Hey Paul,? I don't speak motor so probably stupid question.? Had my compression checked on my '91 Spirit,? 90k, they were all very close to 120psi. Mechanic seems to think that's OK, your opinion? Would adjusting valves improve compression? Ty Dan On Sun, Nov 26, 2023, 10:36 AM Paul Cherubini <monarch@...> wrote:
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开云体育
That’s good news. Your actual compression numbers were likely much higher, but your mechanic didn’t use the correct measuring procedure to get high readings. ?Adjusting valves wouldn’t improve numbers that are normal to begin with. Paul |
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Ty Paul. May get him to do it anyway in spring due to my mileage,? plus he owes me some hours as we exchange labor lol.? I won't sweat the 120 reading then On Sun, Nov 26, 2023, 11:22 AM Paul Cherubini <monarch@...> wrote:
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Sweet. My SpiritLump meets those specs.? Ty again.? On Sun, Nov 26, 2023, 11:58 AM rz <zaveson@...> wrote: rule of thumb.? all compression numbers within 10% of each other, and all over 100 |
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There are a lot of different opinions on valve adjustments on the 3vze and 5vze motors. If you will Google it you will find a lot of certified Toyota mechanics say to just leave them alone. On my 5vze I could hear one of the valves clicking so I went ahead and adjusted all of them even though my mechanic brother said to just leave it alone.
As for the check engine light coming on I would not just ignore it or tape over it cuz if you get a real check engine code you won't know because the light stays on all the time and that would drive me crazy too. |
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Others have covered the most pertinent points here so I won't rehash those.
Valve adjustement, unfortunately, is a bit of a "lost art" because so few modern engines (Note: does NOT apply to motorcycles) require them. Or, if they do they often aren't needed until after an initial owner has gotten rid of the vehicle. In decades past, manufacturers specified valve clearance adjustments every 15k or 30k miles. Nowadays most engines have automatic hydraulic adjusters or they use adjustment systems which, with good maintenance,? can go 100k-150k before the valve clearances get far enough out of specification to cause problems. Given the uncertain maintenance history many Toyhomes have and the constant heavy loads the engines are put under, making sure the valve clearances are within spec is a good practice. Buzz L Phoenix, AZ Former '86 Dolphin, '89 HiLux (V6) and '96 Tacoma owner |
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Paul is an extremely experienced mechanic when it comes to these Toyota RV V-6 engines.? ?From what I gather, it is more important that the compression be close to the same on all of them, rather than the actual numbers.? If one is very low (most commonly #6) that's when an adjustment is needed, before any of them burn.? Paul, did I get it right??
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Paul is an extremely experienced mechanic when it comes to these Toyota RV V-6 engines.Experienced with the 4 cyl, but less so with the V6 as I haven’t ever owned one. From what I gather, it is more important that the compression be closeMore or less true. In other words, if a cylinder compression check reveals the compression is high on all 6 cylinders (over about 160+ PSI ) then the owner can skip the more expensive valve clearance check, but should still consider having the compression checked again about every 25,000 miles thereafter. But if compression is under about 150 PSI on some cylinders then the owner knows the exhaust valve clearances on those cylinders have become too tight and their clearances should be adjusted (loosened) soon to prevent severe valve burning and permanent total loss of compression. Paul Cherubini |
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Update:
The new local mechanic said he couldn't adjust the valves, and didn't know anyone who could. He could do the compression test but hasn't gotten back to me about cost. So far they have only tuned up the engine (said plugs were fouled and some had incorrect gap) on the search for why the check engine light is on (my Bosch engine tester said both "engine runs lean" and "engine runs rich"). I seriously doubt that is what is going on, but I guess it needed done anyway. They are going to try to work on it more next week. Called nearest Toyota Dealer, and the gal at the service desk quoted $310 to do compression test, and sure they could adjust....until she called back and said she'd spoken with the lead mechanic, who said that on an engine this old, if a valve had low compression, it would need a new engine instead of shims. The reasoning was that little rubber bits around the valves would tear up during the adjustment, and it would kill the valve and you'd be back to engine replacement anyhow. My motor-head daughter, who worked several years as Asst Mgr in parts, told me that if the camper had valves checked and adjusted every 30K miles, it might have helped, but to do a first one at 100K miles, it may not be recommended. I haven't had the camper the entire time but I don't think it's ever been done. Sheesh. And of course I was mixing up "compression" with "checking valve clearance." So I guess I have to get back with my local guy and ask if he can do THAT. Of course, now I have TWO campers of the same age! The 93 Warrior rear dinette has the 100k, the 92 Itasca rear bath has 33K. Thanks guys! Sue |
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On Thu, Nov 30, 2023 at 01:36 PM, drscrowe wrote:
if a valve had low compression, it would need a new engine instead of shims. The reasoning was that little rubber bits around the valves would tear up during the adjustment, and it would kill the valve and you'd be back to engine replacement anyhow. This does not make mechanical sense. Maybe there was a miscommunication along the way? I can imagine if they find low compression and find it's due to a valve or valve seat that has been damaged by lack of adjustment, then they'd rather just replace the whole engine rather than removing the cylinder head(s) and having a "valve job" done on them. Perhaps that's what they meant to communicate. The valve adjustment itself (if done properly) will not harm the engine in any way.? But it is expensive and cannot correct any damage that may have already been done. It's too bad your mechanic didn't do the compression test while he was changing the spark plugs. That would have been the opportune time. Good luck, Buzz L. Phoenix, AZ Former '86 Dolphin 500 owner |
开云体育I hope they didn’t screw up the tune up. These are the only two spark plugs that should be installed in the V6 (although equivalent NGK brand nickel (not platinum) plugs could also work): They are both factory original Denso’s and come pre-gapped so? no adjustment needed.? The red and white box ones are purchased? from Toyota dealers. The blue and white box ones can be ordered? from auto parts stores. ?If the wrong plugs were installed or physically damaged during installation it’s possible the check engine light might? come on. It’s only partially true that “if a valve had low compression, it would? need a new engine instead of shims.”? True only if a cylinder had? zero compression, but if around 75-150 PSI then a thinner shim? can often fix the low compression as was demonstrated at the 1:10? mark in this video:? ? All your six intake valves?and even some of your six exhaust? valves likely still have correct valve clearances?even though? no one ever checked and adjusted them. But there are two or three exhaust valves?that may now have overly? tight clearances which in turn can cause low compression numbers on? those cylinders.? Thus if the Toyota dealer did the $300 compression? test and all six cylinders had good compression it would be safe to? assume all the six exhaust valve clearances on the engine are still? within spec or close to it.? Bottom line is everyone you have dealt with so far seems to be only semi-competent. ?The Toyota dealer mistakenly told you the valve? clearances cannot be adjusted because the engine is old. And? your local guy who says he doesn’t know how to adjust them. ? Now the big question is: Can either your dealer or the local guy? perform a compression test competently and honestly? Paul Cherubini |
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lean rich can happen with fowled plugs caused by dirty injectors
low compression caused by tight valve doesn't mean new engine little rubber bits is bull.? i think he doesn't want the job if a valve is tight it needs adjustment- miles not withstanding ? ?so compression check can point to a tight valve, but doesn't show the one that's on the verge? of being too tight causing compression loss -- rz |
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The dealer was mistaken to claim “that little rubber bits around the valves would tear up during the adjustment, and it would kill the valve”?? There are no rubber parts anywhere in the vicinity of the valve? adjusting mechanism that could be torn up.??This short video? shows exactly how?the old valve shim is removed and a new? thinner one is installed on the same 3VZ-E engine you have? (notice no rubber parts are involved) |
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Sue,
This is not you you want to hear, but when I burned a valve in my winnie, those where the two codes that I was getting. To rich & too lean. I found my issue with a compression test. 2 cylinders were really low...like 30psi. I just had an inexpensive screw in compression tester. If you have a friend that is even a little mechanically inclined, its not hard to take out a spark plug, screw in the compression tester and crank the engine. Check the reading on the tester. Unscrew it, replace the spark plug and move to the next plug and repeat the process for all 6. This may not be the "proper" way to get the "true" reading, but you want consistency. For example if the 1st three cylinders come in close to each other, say 110, 120, 115....then the 4th one comes in at 30, then you have a problem. If they are all similar than you have some other issue. Make sense?? -- JohnJab01 |
rz
EDWARD NELSON
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