So carried the car to the mechanic to find out i have 70% leakdown on my 4th cylinder. He says probably cracked, broke piston or piston rings. He also checked to make sure car wasnt over rev and no dents in piston nor bent or floated valves.


Question is whats the correct way about going with this.... another used motor or 4k in fixing it??

 

Used motor with good compression numbers + timing belt & water pump, etc. I think the J35A8 can also be found in various model years of the RL.

The 4th cylinder is the most susceptible to running lean because it is at the end of the returnless fuel system. A bad batch of gas and some high rpm runs could have made it detonate or go dangerously lean if there was fuel system issue.

Did you check the spark plug? I've heard of the #4 plug backing itself out.

 

Uh, so what is the original symptom, why did you bring it to the mechanic? Misfires, uneven idle? Unless he as a scope, he can't see if the valves made contact with the pistons and even then it's hard to see. 6mt or 5at?

The leakdown is done through the sparkplug hole so that eliminates the sparkplug. The mechanic can do a more thorough investigation before pulling the heads. Squirt oil in the cylinder and retest. If it gets better it's rings. If not it's valves. If it's a valve, pull the intake off and listen if you can hear the hissing on the inlet side or pull the exhaust back from the head and see if you can hear hissing from the exhaust side.

It can even be a headgasket. Any loss of coolant, any funny smells from the exhaust, any water in the oil?

Most importantly, how many miles are on it and has it ever had a valve adjustment?

 

Does Acura spec 5w-20 for the TL-S?

 

Yes

 

he did the dry test and wet test. He said after that he did the leak down and could hear the air coming through the oil fill cap
This car is 6mt and i still do not know what could have caused this. He stuck a camera inside the head and no piston to valve contact was made.

 

You will always hear some air getting past the rings. It depends on how much was getting past the rings.

You can't always see piston to valve contact even with the heads off, much less with a camera in the spark plug hole.

So, what are the original symptoms, why did you bring the car to the mechanic in the first place?

 

I'd pull the head and check the valves before making a decision. The used TL-S engines aren't cheap, $3-$4,000, so you might want to look into a new Acura block assembly:
Part# 10002-RDB-A00 List $3027 Net $2270.

Looks complete even with an oil pan, so do the heads, slap them onto the new engine and you'll be good to go and know what you have, rather than the used route.

Just curous, how many miles on the car.

 

The car is idling really rough. the check engine light was on and its saying that its misfiring across all cylinders??
It has 63,000 miles.

 

have you ever over-revved?

 

my guess is

 

me personally never over revd the car but i brought the car in for a SLIGHT hesitation. Acura did some test and said the EGR valve needed to be replaced. Called me and said the car was finished. I then got in the car and noticed the car was still idling funny but i drove through the parking lot to exit the lot. Right as i was about to exit the check engine came on... i then just backed right back up and pulled back to the service bay. That is when they said the car had been over revd ??????

 

This would have been great info from the beginning. The car was overreved at one time. The exhaust valves were initially slighlty bent, now they're burned which is why it got worse. Seeing piston to valve contact with a scope can be hard anyway. Seeing piston to valve contact that potentially happened thousands of miles ago is nearly impossible.

To tell you the truth, 70% leakdown for a bent valve is not that bad. It's easy to get 100% leakdown and the valve will still look good to the eye.

Now you have to choose to have the heads rebuilt or to install used heads. It's too bad you don't have someone that can do it for you, it's going to be expensive but it's 80% labor.

 

Well i am very mechanically inclined when it comes to things like this. Would it be best to just take the initial head off that is having the problem and have a machine shop look at it??

BTW I HATE CARS i really appreciate your input as i have read many articles from you and mostly in the Turbo Thread.

 

yes!! take the head off and send it off to a machine shop!!

or you can go the used route.
depending on which one is cheaper!

 

lol are we joking/smartass here or being serious.... i really do need quality advice and if thats what exactly needs to be done i can do it!

 

my buddy sent his heads to be machined because of an over-rev condition.
he was installing it, but got the timing wrong and bent some more shit.

instead of doing it wrong again, he got his mechanic to install used heads.
here's the thread: https://acurazine.com/forums/showthread.php?p=13468849

so the decision is yours.

 

I'd redo the heads. Used 3.5 heads for the TLS are not common, especially the front head, and will run $8-$1000 for the set. But you've got to make certain there is no problems with the bottom end or all the work will be for naught.

 

There's nothing that can happen to the bottom end to give a misfire across all cylinders short of it being run out of oil. Surely it's possible but there would be noises associated with running out of oil and damage bad enough to cause a major loss of compression.

You can always pull the catalytic converters off the head or even back a little since you have to do that anyway and stick some compressed air in the spark plug hole to confirm the air comes out of the exhaust side (with the exhaust valves on that cylinder closed). You'll always hear some air getting past the rings in the crank case (through the oil fill hole) but there should never be any air getting past the valves.

You can have the heads rebuilt (seats, exhaust valves, guides, and seals) usually for a reasonable price. If you pull the heads off yourself, you should be under $1k for the whole job including the labor to rebuild the heads. You can see how much the shop will knock off if you disassemble the heads yourself but it's not a novice job and you'll likely have to buy a valve spring compressor.

I don't want to be insulting but it can't hurt to check valve lash before you pull the heads. It's extremely unlikely and nearly impossible but if the valves were too tight it would cause the same problems. At 60k I would say there's a .1% chance. You never know if the previous owner tried to adjust his own valves for some reason and set them too tight.

 

so i guess the ECU logged the over rev and that's why this is not warrantied?

 

Well im hoping its just the head also but i want to also say that Acura has already under warranty replaced this head. I am not sure if they correctly reinstalled this new head or not?? Once Acura saw the overrev code that came up while i was in the parking lot th they said they would not touch the car. I am pulling more towards a mechanic was hot roding my car on test drive and that is when the code pulled.

I am the very first owner of this car btw

 

Would it help that i post what it sounds like coming out of the exhaust?? (car running)

 

Well if there was no overrev when they serviced the car the first time and you brought it right back to them without leaving the lot.....you might want to start pushing them. They would have told you over rev on the first repair.....

 

Doesnt it log the time and date of the over rev as well?!?!?!?!?!??!

*crossing fingers that it does*
you'll neeed an HDS to see this info

 

Wait. What?!?!?

You have never over-revved the car. After taking to the shop, it now has an over-rev condition?

I'm no math genius, but even I know 1 + 1 = 2.

Why aren't you pushing the dealer/mechanic to prove (via ECU logging) the over-rev condition?

Does anyone if a date/time code is logged with the over-rev? Is the over-rev in fact logged in the ECU or is that just rumor?

 

I would really hope that it does do data logging cause then thats what i could hold against them. Right now they say that they didnt and i say i didnt. But the car went in for a rough idle to come out with a ROUGHER idle and an overrev code

 

ASK THEM TO USE THE HDS SCANNER TOOL.
I REALLY DO BELIEVE IT STORES THE DATE AND TIME.
a

 

Noob question but how does the over rev code work? If it’s done it throws a code immediately? And isn’t there a rev limiter to prevent this?

 

There's a revlimiter that shuts down fuel and/or spark but if you downshift to the wrong gear, the ECU can shut the fuel off all it wants but the engine is still mechanically linked to the wheels. It's going to over rev even if the engine is technically "off". It's the same concept as coasting down hill with your foot off the gas and the trans in gear. The engine is technically off since the fuel injectors are off but the wheels are keeping the engine spinning.

If there is an over rev the ECU stores the RPM and I think the date that it happened. It's a good diagnostic tool and it's a good tattle tale for warranty purposes.

 

Thanks and sorry for the bold format, copy/paste thing and I can't edit yet.

Is there a way to pull the code history in an ECU, like a vagcom for Honda.

Don't mean to threadjack and I don't think I personally have any issues but I'd love to be able to verify.

 

THE HDS!
HOW COME NO ONE EVER READS MY INPUT!??!?!?!?
a

 

I saw that and looked them up and they are $$
Was hoping there was something like the Vagcom tool for VWs that is the ODBII to USB where you could read the code history with a laptop.

And does the ECU store a history of every code every thrown or does it clear out if reset?

 

^ some codes are hard set and some clear out after a certain number of drive cycles or milage.

Only some TL would know the date and time (the ones with Navi) so wouldn't honda just record the engine hours that it happened at?

 

^correct, the freakin HDS tool from Honda.

only Honda and Acura dealers have this. no, you wont be able to buy it.
have them scan your car with the HDS.
Honda Diagnostic Scan tool, or something like that.

 

Kind of random but tl has a code for over rev??

 

the fuck man, didnt you read!?

I believe the code is stored on the ECU and you will need the HDS to access this.

this is the 5th freaking time I mentioned the HDS, i swear no one reads.
if some one asks another question about the HDS...

 

Justin, I searched but couldn't find the answer. Does the TL store overrev codes and how would you read them if it does?

 

^you have an auto

 

I just wanted to make sure what i read was accurate sorry.

 

its called the Honda Diagnostic Scan tool, or something like that.
only honda and acura dealers have this.

why do you ask?
do you suspect an over-rev?