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Inspect Valve Clearance

Hi

I have a 07 MDX with 102k miles. I had the dealer change out a timing belt/other parts($800) already. I did the spark plugs myself.

A service called valve clearance inspection is recommended. It is pretty expense at $450 and beyond my capabilities removing the intake etc beyond putting feeler guages in. A Honda tech says $350 and dealer is $450. Honda tech states not required if valves not noisy typically.

Opinions?

An otic inspection is first done to determine if the valve lash requires adjustment.

Tester

Valve lash is something that should be inspected about every 30k miles although I’m fully aware that many people do not do this either out of lack of knowledge of the subject or because it can be a heavy financial hit.

That recommendation you were told about only inspecting them when noisy is actually a ludicrous one.
Many car makers other than Honda state the same thing and many mechanics blindly follow this bogus advice.

What is not mentioned is that excessively loose valve lash can be determined audibly but what cannot be determined by the ears is whether or not a valve is tightening up or not. The quiet ones are the ones that can cause you the most grief because those are the ones that may burn a valve face and valve seat in the cylinder head. This is usually more applicable to exhaust valves due to valve stem stretch, etc.

The downside to loose valve lash is that cam lobes, valve adjusters, valve stems, etc take a beating and the engine loses a tiny bit of performance although you may not notice the latter.

Why does the “intake” have to be removed?

Fwd v6 often has part of the intake manifold blocking access to rear 3 cylinders.

http://classic.artsautomotive.com/HondaV6ValveAdjustment.htm

@andrewRA do not go to that “Honda tech” for any work

If he is doesn’t understand the importance of checking and adjusting valve lash, EVEN IF THE VALVES ARE NOT NOISY, he may also be mistaken about other things.

Hondas and Acuras are well known for having misfires and burnt valves due to insufficient valve lash that has been ignored too long.

I suspect “Honda tech” hasn’t yet run into this.

It sounds like Honda needs to get with the program and use hydraulic valve lifters like almost everyone else. It’s not easy to understand their resistance to these, available since the early 1930s. Perhaps it’s a cost savings to not use them.

Personally, I would take hydraulic lifters over mechanical lifters any day of the week. The solids are ok on a race track.

Even though Harley Davidsons are perceived as stone age machines, even HD started using hydraulics in 1948.

Yup, valve lash doesn’t loosen up, it usually tightens. As the valve face and seat wear, the valve stem pokes higher and closes the gap. I used to say to skip it after 60,000 miles if it has been checked and adjusted at 30,000 and 60,000 miles but these engines today are a bit more expensive and will run a long time if maintenance is done right. 1976 was 37 years ago. I just noticed that a few weeks ago.

Then you do a visual inspection for a Check Engine light or if there are any pending codes. Because if the valves go out of adjustment it’s going to cause a misfire which will either cause the Check Engine light to come on, or set a pending code.

Tester

If I had a car that cost $800 to replace a timing belt and $450 to adjust the valves every 30k miles, I would sell it for whatever I could get and NEVER buy another one!!
I agree with others here, they should use hydraulic lifters, with clean oil, they will usually last the lifetime of the engine.

Maybe the hydraulic lifters aren’t compatible with the V-TEC design. Thanks for the infor on the intake manifold, glad I got the 4 cyl.

The car is a bit more expensive than anticipated. I thought all recent Honda was timing chains but this wonderful otherwise V6 motor dates to the 1990’s. At least I purchased it on the cheap at wholesale pricing with 82,000 miles.

This service work only happens every 105,000 miles including spark plugs. Looks a prudent thing to do sometime in next year.

At least servicing it otherwise is dead simple including spark plugs, transmission oil, diff changes etc.

@Tester wrote: “if the valves go out of adjustment it’s going to cause a misfire”

By the time a tight valve causes a misfire it could be toasted.

OK 4450- the site you posted the link to said they have seen no unusual wear on the 6 cylinder valvetrains and they concluded that the 105000 interval to adjust the valves on the V6 is just about right.

@circuitsmith

Nope! If a valve goes out of adjustment the Check Engine light will come on. And if it’s really out of adjustment the Check Engine light will start flashing.

Tester

Honda recommends checking the valve clearance every 105K miles. If it has never been done, then you should have the valve clearances checked and adjusted. If the valves are quiet, you can skip it but you are risking a more expensive repair if the valves are not properly adjusted.

Most likely you can skip it. But, a burned valve can be a pricey repair - so it is a gamble.

HONDA’S ADVICE TO ONLY CHECK VALVE LASH IF THEY’RE NOISY IS ABSOLUTE BS

WHOEVER THOUGHT OF THAT HAS BEEN SITTING BEHIND A DESK TOO LONG

OR MAYBE THEY NEVER ACTUALLY WORKED ON CARS

I’ve owned Honda’s and my two daughters drive Honda’s now.

The Honda’s I’ve owned were purchased with failed timing belts for cheap. Once the head work was done from the failed timing belts, the valve lash was adjusted to spec and never touched again. And we’re talking 200K miles without touching the valve lash.

Tester