TXFred

This is a bit of a long story. I have a 2004 Value Package Coupe. At 69,000 miles, I replaced the timing belt and adjusted the valves. I did not replace the water pump. I removed and inspected the tensioner. It appeared to be in good condition, so I reinstalled it.

Two weeks ago, with 89,000 miles on the car, I sold it to a friend and neighbor. Two days ago, it lost compression on all four cylinders.

I took the head off, and here's what I found.

The spring on the timing belt tensioner had rubbed its way through the loop on the timing belt tensioner. It then dropped off, got caught in the timing belt, and wound up jammed between the crank position sensor and the timing belt. The timing belt skipped a tooth, and the car was down on power for a couple of days. Then it skipped another tooth, and the valves collided with the pistons.

There is a steel insert that fits in the loop on the tensioner where the spring attaches. This insert is gone. The only remaining piece of it is a small chunk wedged in the remains of the spring.

What I want to know is, is this due to something that I did wrong when I changed timing belts? If so, what was it? I don't want to make the same mistake again.

When doing the work, I used this thread. I also followed the instructions in my Haynes manual. I have done timing belt replacements before, and know how critical they are. I always do them step by step, with no shortcuts taken. I'm pretty OCD about my vehicles, to the point that I won't even drink a beer while I'm working on a car.

But I'm pretty sure that I made a mistake.

I've treated this like an episode of CSI. Everything was photographed and documented in position before I moved it or undid any bolts. I've attached pictures of the tensioner in position on the car, the tensioner removed from the car, and some shots of the spring.

The first four pictures are collages that I made by sticking the camera down into the engine bay and taking pictures of the tensioner. Nothing has been moved. The tensioner is in the exact position that it was in when I removed the timing covers.

There is no argument between my neighbor and I. I'm not trying to gather evidence in case of a lawsuit. She is willing to accept that s&*t happens, and is willing to pay for repairs. I am willing to believe that this is my fault, and I am also willing to pay for repairs. My reputation is worth more than the cost of the repairs, so I'm not going to screw over a friend. We just want to know why this happened, and how to prevent it from happening again.

Thanks for taking the time to read this. I look forward to your responses.

Frederic

BlueEM2

iTrader: (1)

Ohhh man... it's hard to say but I'm willing to bet it's install error. Did you put the spring on the right way? If you do it backwards it could do damage but to go through the loop like that is odd. Is it an OEM belt?

I'd say more than likely its something that you did however I cannot pinpoint what it is.

TXFred

Also, here's shots of the four pistons. The damage is very light. The engine turns freely, and there's no sign of cylinder wall damage.

I'm of the opinion that they are still usable. What do you think? Reuse, or replace?

TXFred

I don't know if the spring was on backwards. It's so beat up that there's no way to tell which end was which. Maybe once I have a replacement spring, I can compare and figure something out.

The belt was from OReilly Auto. The belt looks good other than damage from where it was rubbing or catching against the spring.

Frederic

BlueEM2

iTrader: (1)

I'm just wondering if a non OEM belt with an improper tooth configuration or length could have caused too much tension to be on the tensioner spring. However, The tensioner should compensate for that... hmmm... Hopefully someone that knows a bit more about this can chime in here.

Those pistons are shot. I wouldn't use them anyway. Piston dings become hotspots which can cause further problems down the line.

I'm almost willing to betting the spring was on backwards.

TXFred

What if I filed or otherwise smoothed the damaged areas? That should eliminate hot spots. But I'm still concerned about structural damage to the pistons.

Other than Honda, are there good sources for pistons and valves? I am seeking lower cost, but not at the expense of lower quality.

Frederic

BlueEM2

iTrader: (1)

The structural damage would actually be to the connecting rods.

Replace the block.. that's your fix. Junkyards will sell whole engines for around 600 dollars. Once you buy one, replace the head gasket/timing belt/tensioner/water pump/clutch/p.s. belt/accessory belt/spark plugs and essentially all other seals you come across and you should be good to go.

You can of course get the new head checked for trueness to make sure its good. This way all the engines maintenance is taken care of and your neighbour will be set. All this will run you about 1300-1500 if you do the work yourself. Assuming you know how to change an engine. <That price assumes you bought the engine for around 5-600.

ezone

The tensioner hole worn through is something that they do, that's a big part of why everyone says to replace the tensioner set (pulley and spring).

I haven't seen one toasted at that early of a mileage so far....In fact, the only one I have seen like that (so far) went to 250,000 miles before it did.

WHY it wore through is a guessing game.
I can guess just wear, not the fault of the spring or anything. The spring hook is the same on both ends, so you can't get it backwards.

What would cause the wear? Excessive movement. If the belt had a thick spot that caused the tensioner to move excessively every time the belt went around, I could understand that may be a cause.

Aftermarket belt? Sure could be a possibility.
Was it a Gates belt? Was it an off brand?

Too late now, just get OEM parts to put it back together.

My concern is always that the dents in the pistons can make the top ring bind. Depends on the depth and how close to the ring groove the dents are.

I don't have a concern about hot spots because of the dents.

Most customers only opt to do the valves and run it that way. Usually turns out ok. I always warn of the possibilities like compression loss and oil consumption.

Nobody has opted for me to yank pistons to check the rings yet, so I don't know what the chances are that it actually happens on this engine.

TXFred

Ezone, it sounds like you've done a lot of these. How many have you done, at a guess, and how many worked out OK with just a top end rebuild? I'm trying to work out a probability of success.

I'm still considering the best way to fix this. It's either an engine replacement or a top end rebuild. There are good arguments for both. And I have a lead on an engine from a fellow who's Civic was towed improperly, destroying the transaxle. His engine should be in good shape. But I'll need to check it out and talk the price down.

I know engines fairly well, and could swap a motor if needed. But if it comes to that, I'm going to just write a check to a mechanic and get on with my day.

The belt is a Gates belt, made in the USA. I checked it with calipers, and its thickness from valley to valley varies by +/- 0.005". Peak to peak, it varies by +/- 0.002".

I've got a theory now. The loop for the spring on the tensioner is stamped steel, with a hardened steel insert pressed in. It appears that the insert on my tensioner worked loose, leaving the hardened spring riding on the soft stamped steel. Add vibration, and it was only a matter of time.

Also, look back at the pictures of the tensioner. There is a broken off tab. The purpose of that tab appears to be to limit the travel of the tensioner. I don't know how that tab broke, but it's gone.

Frederic

ezone

The tab is a travel limiter, it probably got slammed and broke off.
Gates makes some of the timing belts for the factory.

If the eyelet for the spring was already gone, your theory is probably right. Mazda had a big problem with this same issue on some of their timing belt tensioners in the mid 90s, there was a recall on it. Real Mazda built Mazdas didn't bend valves though.

I've been at this dealer since 03, and it's small. In my time here I've seen maybe a dozen engines that trashed the timing belt (more than just Civics). Probably only fixed half of them or less, the rest got dragged to someone cheaper, or junked.
Most of the cars that break belts aren't owned by regular customers.

The only ones that have a chance are the ones that strip the belt while cranking the engine, or it was idling when it let go.
If it was running fast when the belt let go, the chances are great that the valves are bent.

I've seen many more cars than just Hondas with bent valves, I've been doing this most of my life.
Quite often, by the time the car is on its second or third owner and the miles and neglect are high, the car just isn't worth fixing.

TXFred

I picked up a used engine today and hauled it home. Now that I have it back at the house, I have discovered one difference. The new engine, from an 01, does not have an EGR valve.

I wonder what problems this will lead to, such as a CEL. Can I simply swap the EGR manifold from the old engine onto the new one? Hopefully the cylinder head itself isn't any different. If it is, then I am going to have to return this engine.

TXFred

Ignore that. The repair shop turns out to have an 01 Civic engine, with EGR, and in better condition, for less than what I paid for the first engine. So the EGRless engine can be taken back for a refund.

And to answer my own question, swapping the EGR/Coolant manifold would have solved the issue.

ezone

Yeah, swapping all necessary parts would have been part of the job. That includes manifolds and all the little stuff to make the new engine work like your old one. Really, you are swapping the block and head, not everything else, unless it is all the exact same.

BlueEM2

iTrader: (1)

Yep, while the engine is naked it might be a good idea to replace the head gasket, timing belt, water pump.. and all other stuff I listed above.

ezone

Yes, absolutely. DO all possible maintenance items while it is out of the car and easy to do. Make it so it is ready for a long life before it goes in.

TXFred

Update time. The car is back together and has been running great for weeks now.

The mechanic put the "good" engine in, and then found out that it had almost no compression.

So after checking out the pistons again, we rebuilt the original engine's top end. 8 new intake valves and a top end gasket set later, and it's back in business. The valve seats took no damage, and the new valves lapped into place in no time at all.

The engine got a new water pump, timing belt, tensioner, and seals. So it should be good for quite a while.

For the sake of my sanity, I had the mechanic reassemble the engine. That way, if something goes wrong, it's not my fault.

Thanks for all the help and advice.

Frederic

04 Honda Civic

iTrader: (2)

I have read that reusing the old tensioner is a bad idea. They tend to fail after you touch them. I dont know if that was why this one failed, but it would probably be a good guess of what happened.