2007 Honda Pilot 3.5 multiple misfires

[Number_35]

Here are the #5 and #6 spark plugs:

However, the problem turned out to be the timing belt. After removing the serpentine belt and the P/S pump bolts, the pump can be moved far enough (without removing the hydraulic hoses) to remove the upper TB cover on the inner (closer to the firewall) bank (Cylinders 1 to 3).

The timing belt is cracked and has a lot of slack in it. It's almost certain the hydraulic tensioner has failed. I would bet the belt, tensioner, WP, and idler pulley are all original.

It was around -11°C earlier, and I worked slowly, with lots of tool trips back to my house (5 houses away), combined with warm-up breaks for my hands.

I can't do this job properly working outside in the snow. I told my friend I can do the work in April or May when it warms up, or he can have it towed to a shop. (I can put it back together as-is, but the vehicle should not be driven - it's already skipped at least one tooth, and another skip might mean the end for this interference engine. As well, the misfires would damage the cat quickly.

 

[Number_35]

If I do the work, I would probably buy a kit from RA. Aisin has been mentioned favourably here on BITOG.

Are any of the other manufacturers better?

If Aisin, is there any advantage in going with the THK002KR over the basic THK002?

Thanks!

 

[D60]

At 12F? You're insane. I might check tire pressure at that temperature.

I'm willing to be outside and work, but I can't do anything that requires dexterity. Then again I believe I have Raynaud's in my hands.

GREAT FIND and you should revive this thread in the spring if you do the work!!

 

[GSCJR]

At 12F? You're insane. I might check tire pressure at that temperature.

I just declined doing an oil cooler on a Pentastar; it's snowing and -4c right now. I'm turning into a snowflake as I age.

 

[Number_35]

At 12F? You're insane. I might check tire pressure at that temperature.

I'm willing to be outside and work, but I can't do anything that requires dexterity. Then again I believe I have Raynaud's in my hands.

GREAT FIND and you should revive this thread in the spring if you do the work!!

Like you, I may have Raynaud's - no formal diagnosis, but my fingers get cold very quickly. I have battery-heated gloves for winter cycling.

Unfortunately I have trouble working with gloves on, so was doffing the mitts frequently today.

The Pilot owners are such excellent people that I was fine with getting cold hands to find out what was going on.

I will update this thread as things develop.

 

[Number_35]

I just declined doing an oil cooler on a Pentastar; it's snowing and -4c right now. I'm turning into a snowflake as I age.

I don't blame you at all - that's pretty fiddly work in freezing temperatures.

Ditto with this Honda TB - I think there's a good chance I'd mess something up working in the cold.

 

[Devo242]

If Aisin, is there any advantage in going with the THK002KR over the basic THK002?

Judging from the photos the belts both seem to be Mitsuboshi and the water pumps from Aisin, the most obvious difference is the bearings.

THK002 appear to have the look of Koyo or NSK bearings (red seal), THK002KR bearings appear to be NTN and made in Japan based on the markings visible (blue seal).

For less than $14 price difference I'd probably pay the extra, but I think either choice is fine.

 

[brages]

I think the Koyo bearings in the Thk-002 kit have changed from red to blue over the years. I don't know what's in the kr kit.

 

[Number_35]

The owners have decided to have the Pilot towed to a trusted shop and have the TB, WP, tensioner, and idler pulley replaced there, rather than waiting c. 3 months for me to be able to it.

Their daughter works at a dealership, and with family pricing they are getting a good price - C$1200 including the tow.

 

[Number_35]

Update: The shop installed the Aisin timing kit (belt, tensioner, tensioner pulley, idler pulley, and water pump), but the engine continued to misfire on two cylinders. A borescope inspection showed two bad valves. In the one photo I saw, the valve had a jagged chunk missing.

The owners have decided to sell it as-is rather than repairing it.

They would like to replace it with something similar. This afternoon we looked a 2008 Acura equivalent (MDX?). It looked pretty good, and drove well, and had c. 197,000 km on the odometer (not bad for a vehicle coming up on 17 years old).

My friends wisely ordered a Carfax report, which showed the mileage increasing steadily to 210,000 km by 2015, and then being sold to the present owners two years ago at 162,000 km, so racking up negative 48,000 km over eight years.

Obviously something's up ... the search will continue.

 

[Number_35]

Further to above, I wonder whether the odometer had been switched over from kilometers to miles at some point before the present owners (who seem honest) bought it.

2015 - 210,000 km

2022 - vehicle registered with 162,000 on odometer (assumed to be km). If 162,000 miles, this would be c. 260,000 km, so only 50,000 km would have accumulated between 2015 and 2022. Low, but not impossible.

Late 2024/early 2025 - odometer now reads c. 194,000. If km, someone has tampered with the odometer or replaced it since 2015. If in miles, the equivalent is somewhat > 300,000 km.

 

[brages]

Thanks for the conclusion. Burned valves are not unheard of for J35s, since I am sure only a minority of owners adjust them.

 

[KrisZ]

Wow, the shop charged for a new TB and all the trimmings, and then decided to boroskope the valves? A bunch of hacks.

 

[Number_35]

Wow, the shop charged for a new TB and all the trimmings, and then decided to boroskope the valves? A bunch of hacks.

I don't have a borescope, but am now considering getting one. If the owners had waited until I could do the job, I also would have changed the TB and assumed all would be well, with the same outcome - although at least the owners would have saved the labour cost.

Agreed, having been told that the vehicle had been driven c. 30 to 50 km while misfiring, and knowing that the TB was quite slack, perhaps a professional mechanic should have investigated further before changing the TB.

Back in the late '90s I changed out two broken timing belts for friends, where the vehicles had failed - one in a backyard, and one pushed into a friend's driveway. One vehicle was late '80s Accord, the other a mid-'80s Tercel. I had assumed both had interference engines and warned the owners there might be engine damage, and yet both engines were fine with a new belt. As a result of this, I thought the dangers of interference engines were overstated. Nope, lesson learned!