adam83

So awhile ago my 2004 TL automatic 160k miles started idling low while driving, then went back to normal after a few seconds. I pulled into gas station, filled up, then started up and went down to the store. As I was pulling into a parking space, the car idled low again and died. wouldnt start. No bad noises at time of breakdown, and no bad noises when cranking. My first thought was fuel pressure relay. After hours of checking out and testing fuel and spark system, a friend of mine loosened the left top timing cover and peaked inside... Belt didnt move while cranking.

So I took apart the front of the engine today. The timing belt teeth were shredded at the crank sprocket. I removed all pulleys, tensioner and the belt. All pulleys and wp pulley turned great. The left cam sprocket turns easy, crank turns easy. Right cam sprocket is frozen. Something very bad has happened inside that head.

Im going to remove the heads (no other choice) and investigate further. What I cant tell is if the problem started with the belt or the head. The sprocket froze, and that stopped the belt from moving which is why the crank sprocket tore it up, but why did the cam freeze up? Either the belt jumped or fell apart at the crank then valves got bent in that head locking it up, OR, something happened in that head, froze the cam and stopped the belt then the crank tore it up.

No issues with the car before this. Bought the car about 7k miles ago from a car lot, I guess my confidence in a shiny new used car got the better of me and I didnt think Id need to replace the timing belt for awhile. Lessened learned. But, was it the belt??

paperboy42190

iTrader: (7)

lesson of the day: dont judge a book by its cover. dealers can clean a car all they want, but if the mechanical parts are messed up, then it wont drive as good as it looks.

If I were to guess, I would say something happened in the head that caused the camshaft to get stuck, and caused the timing belt to tear, instead of vice versa

Adobeman

I think I agree with paperboy42190. Now the question is why did the cam freeze and how much other than the head is damaged. Cranking it probably caused pistons to hit valves but were the pistons damaged. You will know when if comes apart. Depending on the failure mode of the head hopefully you will be able to tell if it was a one-off bad luck thing or if there's more to worry about (like the other head doing the same thing soon)

adam83

I'm going to rebuild both heads at the same time. I'm really curious as to what caused the failure because it ran great and had no issues, it just happened out of nowhere

thoiboi

see... i don't buy the 'out of nowhere'..


car has 160K . presumably same timing belt so that's 55K over the specified service interval. Who knows what else the Previous Owner skimped out on in terms of maintenance ya know? bad gas, old plugs, no oil changes.. etc. etc.

adam83

Out of nowhere refers to the head. I agree with you about the belt, but if it was a head failure usually there is some indication that there is a problem with a cam or valvetrain, I've never had a sudden incident like This. Had the car almost 8 months and no chatter, power loss, bogging down, misfire or whine. Always mobile 1 5w20 synthetic and filter. Always premium gas.

thoiboi

I wasn't referring to you. I was referring to the 11 years the car was NOT in your possession prior to you purchasing it.

i mean at the end of the day, it's all conjecture anyway, interested to see what you see what you pull the heads

Adobeman

"No bad noises at time of breakdown, and no bad noises when cranking."
Alex I'm going with "what is a seized cam shaft bearing" for 200 . I've never actually heard of it on a TL. If something broke I would have expected some bad noises. I'm probably way wrong. We'll see.

adam83

Got everything tore down and ready to remove heads. Just need to remove the exhaust studs and I'll be ready to take heads off and see what Im dealing with

paperboy42190

iTrader: (7)

good luck! keep us updated!

nfnsquared

Sub'd for results. Good luck, here's hoping the damage is minimal ....

adam83

Ok got the heads off, bear with me Ill post the full view in a few posts. Here is the top of the block and the cylinders and pistons. NO evidence of valve tap on any of the pistons this leads me to believe my right head cam locked up for some reason.

Here's the top of the block






Right bank






Left bank

adam83

Here is the right cylinder head (the locked up one)

adam83

Heres the left cylinder head, spins freely. I rotated the cam all the way and it looks like every valve opens as it should.

adam83

I decided to leave the heads assembled since Im not familiar with honda heads and let the machine shop disassemble them as they may notice things I am ignorant of while they are being taken apart that will lead to the explanation of why the right head froze.

Im going to start a new Thread about the head rebuild because I have a lot of things I want to ask about the rebuild and gaskets and other things to do while I have the engine this torn down.

thoiboi

dirty heads that's a lot of carbon !

nfnsquared

Huh? One set of intakes looks like maybe excessive carbon build-up, but all the rest look pretty normal to me....

adam83

I took the pictures with my cell phone so they're not the clearest quality but yes I agree with this I think this is fairly normal build up for a motor with 170000 miles

truonghthe

Both head looks clean for a 170k miles car, I don't see any abnormal sign in your pics.

adam83

Agreed. But the right head is locked. My machinists guess was that the cam was starved of oil somehow. They'll be taking them apart this week.

I heard that these heads don't have don't have cam bearings and the can and they can just rides on the aluminum head surface. Is that true?

adam83

The verdict is in. The machine shop called me and the cam journal closest to the sprocket has seized up. The aluminum surface of the head that it rides on is all galled up, and there is aluminum embedded in the cam journal. The debris in the area make it hard to tell if there was gunk blocking the oil hole, but it does look like that journal was starved of oil. They also said that the journals that are closest to the cam sprocket take the most stress from the tension of the timing belt.

So my options are polish the aluminum and out a new cam in, or find a used right head. This would be so much easier if Honda used cam bearings..

Does anyone know the part # of this head? My car is a 2004 Acura TL with an automatic transmission.

What other years/cars was this exact head in? I need to start looking for a used head asap. I'll be getting it as well as my good head freshened up and milled so I can hopefully get another 100k miles out of the car.

truonghthe

10005-RDJ-305 rear bank

10004-RDA-305 front bank

Any 04-06 TL head should be bolt up just fine.

BreezyTL

iTrader: (8)

Where are you located? I have a working motor that is in my car that I am parting out. Maybe we can work something out.

adam83

I'm in Tacoma, WA.

I found a new Honda casting with valves and springs on ebay for $200 free shipping. I may do that and just have the machine shop transfer over everything else from the old head. I would just need a camshaft, and I haven't priced one out yet.

New Honda Acura V6 vtec Cylinder Head Casting RDJ Less Camshaft | eBay


I definitely don't have the time to go to a junk yard and tear down another engine. Breezy how many miles are on that head and how much are you asking for it?

adam83

Just found this complete head for $275

ebay item number 291809177234

NEW Honda Acura V6 VTEC Cylinder Head Casting# RDJ

BreezyTL

iTrader: (8)

196 and some change. Shipping may kill ya due to weight. I don't even know where to start with coming up with a price without seeing whats on the net.

adam83

I think I may just get the complete new head from ebay for $275. The only hesitation I have is that the description says RDJ, not the full part number 10005-RDJ-305

BreezyTL

iTrader: (8)

Let me know if you change your mind. I haven't pulled anything from my motor yet.

Turbonut

iTrader: (1)

From what I can see, the intake camshaft assembly looks dry from lack of lubrication.

adam83

I'm trying to figure out how it got starved of oil. I don't think it's the culprit but I'm probably going to replace the oil pump just to be safe

adam83

I bought the new complete head for $275. The business had sold over 400 heads on eBay including rdj heads with 100% positive feedback, and decent return policy so I felt good about the purchase.

I'll take it to the machine shop when I get it so they can check it out. in the meantime they are rebuilding my left head, new seals and a little valve work. If they mill it I may have them mill the new head to match depending on how much they take off

BreezyTL

iTrader: (8)

Might be wise to have both heads the same?

adam83

Yes the goal is to get the older head as close to new as possible. They said the cam and journals were in excellent shape, so they'll clean the head, possibly polish the journals and seats they ride on, check spring pressures, clean up valves and seats, check and see if it needs to be milled and put in New seals, set lash etc etc.

nole85

i agree with breezy, better rethink this...

adam83

I guess I'm not seeing the point you guys are making, are you referring to the milling?

The whole reason I'm getting the left head completely rebuilt is so it will be as close to new as possible. And if they have to mill the left head, then I'll probably get the right head milled as well. That's the only difference between the 2 heads that is significantly concerning to me.

BreezyTL

iTrader: (8)

We were just saying it may be better to have both the same no matter how much they take off. I am no master engine builder but from common knowledge, I would want both sides damn near the same specs.

adam83

Got my rebuilt head and my new head back from the machine shop. They fully rebuilt the front head (resurface, valve job and R&R camshafts), and inspected the new head. Valve lash set. The amount they surfaced the old head was so minimal that they didnt feel I needed to get the new one milled as well. The total cost for all parts involved, not counting fluid changes:

Rebuild old head: 280
New head: 275
Clean intake manifolds: 25
New upper engine gasket set: 200
Shop supplies: 5
Sales tax: 40.29

total for heads and gaskets: $825.29

Aisin timing belt and water pump kit:174.04
New fuel injectors, thermostat, egr, spark plugs: 333.19

Grand Total: $1332.52

Got everything put back together with new fluids and battery. Started right up, and runs perfect. The only hiccup was I forgot to plug in the cam sensor , so it would'nt rev past 3000, but once I figured that out and plugged it back in, it runs beautifully .

I wonder how much this would have cost at a shop, or dealership?

adam83

Next on my list is to change the tranny fluid and filter, and look into the 3rd/4rth gear switch replacement Ive been hearing about.

thoiboi

wow that's not as bad as i thought!


https://acurazine.com/forums/third-g...2006-a-729149/ DIY is here

truonghthe

There is a member here did similar work because plug #5 blew out, the bill from Acura dealer was around $9k. Fortunate enough he bought the extended warranty from Acura and they ate all cost. he paid like $200.