Inquiring minds want to know: Did Honda publish incorrect valve clearance info?

[dejola]

I've noted that quite a few on this board have mentioned problems with misfires and valve problems. The information I am about to impart may explain some of those problems. I hasten to add that what I write below has not been confirmed, but it has the ring of truth and can fairly easily be confirmed. I am in the process of try to do just that. I have learned that Honda, in a marketing decision, may have decided to publish different recommendations for inspecting valve clearances in the owners manuals of 1997-2001 CR-Vs sold in the United States and Europe. It has been suggested that Honda marketing people felt that sales of the vehicle in the United States might suffer if potential American buyers knew that the valve clearances on the B20 engine had to be checked early and frequently. As the as yet unproven theory goes, the owners manuals of cars sold in Europe recommends that valve clearances be checked and adjusted (if necessary) at 30,000 miles and every 30,000 miles thereafter. The owners manuals of the same cars sold in the United States state that valve clearances should be inspected at 105,000 miles (page 203). If this is true then it would seem the wiser decision to make the early and more frequent inspections and adjustments as necessary. The failure to do so could result in the valves going out of adjustment leading to misfires, valve failure (burnt or damaged) and failure of the catalytic converter. If Honda knew that the valve clearances needed to be checked at 30,000 miles and every 30,000 miles thereafter to avoid the need for very expensive valve jobs and catalytic converter replacement, how could they OMIT that vital information in the owners manuals of cars sold in the U.S.? I am told that in most cases when automoble valves go out of adjustment hey do so on the loose side resulting in noisy valves. Any mechanic and many lay people hearing the sound created by loose valves recognize the sound as a warning that the vehicle needs a valve adjustment. In the case of the B20 engine used in the 1997-2001 Honda CR-V, the valves get tight and make NO noise. So without he correct recommendation about inspecting valve clearances at 30K and every 30K thereafter, and without the benefit of the telltale noisy valves, the average U.S. owner is being led down the primrose path to costly repairs. Honda actually became aware of this problem and issued a Technical Service Bulletin (TSB) #03-038 on December 19, 2003 and again (revised) on November 7, 2004. That bulletin stated that the fix involves replacing the head. It is my understanding that fixing the valves and just machining the head won't fix the problem due to the tolerances involved. This is an issue that has not received any publicity that I know of. But it is one that needs to be explored further. Either Honda published two different owners manual provisions relating to valve clearance inspection requirements or it didn't. I hope to get to the bottom of this. If they did, the one that was published in the U.S. manuals was wrong and costly to lots of CR-V owners.

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[Perfectionist]

If you haven't already, check out hondasuv.com . There were several threads about burned valves due to incorrect adjustment clearances, and the recomendation to check them only when noisy. I haven't followed them lately so I can't guarantee the information would be fresh to you.

[dejola]

Thanks. I appreciate the information. But as I indicated if my information is correct the valves on the B20 engine get tight and don't alert you with noice like loose valves do.

[19slocivic97]

I think your informaiton is correct, the reason honda recommends replacing the head is because the guides sink in the head and cause the clearance to tighten, I'va had a few come through work with missfire codes from the valves being to tight, but generaly it's higher milage crvs between 130-160k, all we do is adjust the valves. I've never seen a head replaced for the problem of the guides.