keantoken

I now have a 1999 Acura TL at 222K miles. It has been continuously maintained.

There is no blow-by when I remove the oil filler cap. Transmission fluid is clear pink and smells fishy by not burnt. Oil is Mobil 1 synthetic, is a bit dark.

I know this is a lot of questions, so don't feel like you have to answer everything.


1: I removed the spark plugs. They are NGK G-power, but they are all under 0.044" gap and look to be in good condition and no oil film. Should I get different plugs?
2: I torqued the plugs to 240inch-LB or 20LB-ft according to NGK. I noticed people here are using less torque but not sure why. Should I loosen them?
3: The passenger headlight spark plug is slightly tan colored whereas the others are all bright white ceramic except for a slight grey flame shadow. I think this means this cylinder is running rich. Injector? Should I check valve lash?
4: Above 2000RPM on acceleration the combustion is uneven, not misfiring but audibly rhythmic with nearly imperceptible vibration. Could this be caused by the one cylinder from #2?
5: I had the impression that the 1999 4-speed transmission was not as fragile as the later years, but in any case it has had regular fluid/filter changes. How do I keep it running well?
6: I have the P0401 code. I was planning on removing the intake and cleaning the EGR passage. I cleaned the throttle plate and it was kind of filthy. Thoughts?
7: The TPS reads 10% at baseline and seems good, but the car tends to accelerate suddenly after a stop which is hard on passengers. On my Ford Taurus this was due to a cheap coilpack, but is there something that can cause this on the Acura? I didn't find any vacuum leaks.
8: The intake air boot is cracking, especially around the throttle body. How to deal with this?

Body:

9: I adjusted the rear view mirror a few times and got the dreaded bubble. Any advice? Is the liquid really corrosive or is that a myth?
10: The pleather seats have some holes and tears, but are pretty much intact except for some of the driver's seat. Is there something I can do to patch and preserve them?
11: The door weatherstrip is cracking in areas exposed to sunlight and the door seals have torn in a few places. Is there a time tested way of preserving these?

keantoken

Another note about #3, the same cylinder with the tan spark plug showed a higher spark voltage. This is consistent with either a richer fuel mixture or higher compression. I can only think of valve lash or a bad injector as a cause for this. Not sure where to go from here.

Karanx7

iTrader: (2)

Welcome to AZine, keantoken.

1. Yes
2. Tighten them to 13lb-ft when you get the correct spark plugs.
3. I wouldn't worry about it.
4. If it's not misfiring, you wouldn't be able to tell.
5. Religion
6. Clean the intake manifold while you're at it.
7. What's your idle RPM?
8. Get a CAI.
9. Yes, it's corrosive. I'd replace it, or take it apart and remove the fluid.
10. You can buy a patch kit or get it professionally repaired.
11. Don't park it outside.

Arkady

For the seats, keep an eye on local junkyards and check out how the seats are doing in there. I've slowly been replacing the leather on my seats as I find good-condition units in the junkyard. I pull the seat out and remove just the "cover", much cheaper that way. Just be sure to give it a good cleaning when you install it!

keantoken

Awesome, thanks.

Idle RPM is 680RPM. MAP pressure reads 4.1PSI.

keantoken

I swapped the first 2 coilpacks, but the first cylinder still had higher spark voltage. So this rules out the coilpack.

I took the front timing cover off. The timing belt looks brand new like it has just been put on.

It has valve noise so I am considering doing a valve adjustment. I suppose maybe I could fit a feeler gauge or wire gauge through the oil filler cap to see what the valve lash there really is.

whitetiger5

It's going to be pretty damned impossible to insert a feeler gauge through the oil filler AND in between the right bits to check for valve clearance.

are you getting any CEL lights or failing smog? if not I would leave it until you are ready to replace all the parts along the way to the valve covers (valve cover gaskets, clean EGR, replace various gaskets/seals, etc) and knock it all out in one go.

it just doesn't seem worth the effort to take everything apart to check valve clearance. It's a lot of disassembly and often folks end up having vacuum leaks when they take things apart and put them back together because they reused parts, didn't torque or assemble them correctly.

I'd source a rear view mirror from a junkyard.

Karanx7

iTrader: (2)

Not sure why you're chasing a potential misfire while still running NGK G-Power.

keantoken

I've tried to cure a misfire by changing plugs in the past with multiple cars and never had much results. Usually it's something about that cylinder, and the spark plug only has a slight effect on the result. We will see when I get the new plugs.

I did the injector balance test and there is nothing about the injector on that cylinder that jumps out. If it's running rich but there is no excess fuel, then it must be because there is too little air. This suggests the valve maybe isn't opening enough, which would point to valve lash or perhaps just lots of crud.

keantoken

When doing the injector balance test, the fuel rail intermittently failed to hold pressure. If I kept the pressure from draining completely I could keep it operable, but when pressure goes to zero it is a gamble whether it will hold pressure after priming. I suspect the check valve in the fuel pump is failing, since there seems to be no trouble maintaining pressure while the fuel pump is running.

Fuel pressure seems correct at 41PSI just after priming and 32PSI while running.

keantoken

There is a sound like a pigeon cooing coming from the belt side of the engine. It's not a pigeon, but maybe one of you is familiar with this sound? Bearing whorl? It seems to be in the range of 400Hz so maybe it is actually the regulator/alternator (which works fine and was replaced recently)?

I put the new spark plugs in, and indexed them since I haven't done that before. At idle there is less valve noise, no longer the distinct valve tapping/spitting noise and the bass from the exhaust is lower. I take this to mean that the cylinder pressure is lower when the exhaust valve opens, meaning I am getting a more complete, more immediate burn. The engine noise is more like a whoosh now. However the one cylinder still has a high spark voltage, so it's very likely the misfire hasn't gone away or will come back over time. This has been the case the last several times I thought I could fix a misfire by changing spark plugs, each time encouraged by forum comments. Not that I don't keep an open mind.

The spark plug in the weird cylinder has a cream colored deposit all over it, like plaque on teeth, and it has black ticks from what looks like arcing over the ribs. I think something really weird happened to this cylinder.

keantoken

I got a new mirror. But weirdly, both the old mirror and new mirror are now loose. I bent the clip to do what I thought would be tightening it, which actually made it looser! So I bent it the other direction and now it is a little better, but I need to try again. I now understand perfectly why people hate this mirror mounting system so much.

After going for a test drive, the engine noise is down to the point where I can hear the cylinder noise more. At idle, probing around with the stethoscope only gives pretty normal engine sounds. So I am looking for a knocking sound which:

1: Only appears while under load above 2000RPM
2: Appears at lower RPM at higher loads
3: Doesn't respond to changing spark plugs

I have basically the same sound on my Taurus and it drives me insane. Maybe one piston is slapping?

thoiboi

What kind of plugs did you put in this time around?


Did you ever do the valve adjustment? Make sure the coilpacks are OEM-spec as well, If the last owner bought G Power plugs, they may have cheaped out on coils as well. OEM is ideal: https://www.oemacuraparts.com/oem-pa...QtYXV0b21hdGlj

Denso here for half the price: https://www.rockauto.com/en/catalog/...tion+coil,7060


NGK Iridium IX here for a fraction of the price as well: https://www.rockauto.com/en/catalog/...park+plug,7212

keantoken

I used Ruthenium plugs. If you want, I'll replace the plug in the weird cylinder with IX just to be sure.

I was reconsidering the valve adjustment since it got much quieter with the new plugs. The intake is totally caked inside with oily crud, so I need to at least take it down that far.

The coilpacks are all Hitachi CM11-207, and engraved 9206 which I suspect is the batch number. Not 207a, so they may have never been replaced! I believe this is the original OEM coil. In any case all coilpacks give the same spark voltage and the one that doesn't will do so if swapped out of the weird cylinder.

keantoken

Where can I get a drivers side lock cylinder? It has the electronic switch.

keantoken

Well that was a dumb question, I had no idea so many parts were available for this car from OEM.

I made a recording of the engine noise. The only thing I can think of is rod knock. I'm using 93 octane gas.

https://drive.google.com/file/d/19L7...ew?usp=sharing

Midnight Mystery

I did the request access thing but if you can post to YouTube it would be better.

keantoken

Sorry about that, everyone should be able to get the recording now.

keantoken

I already took off the rear timing cover and felt for belt tension under the cam sprocket. I did not feel any slack, so I don't think it is the tensioner.

Midnight Mystery

I'm not very knowledgable on this, but it sounds like maybe coil packs or detonation.

Rod knock is different... and very bad.

Are your spark plugs all tght?

I think it's no. 5 on the J-Series V6's that likes to back loose.

keantoken

I already changed the spark plugs, sound was present before and after.

keantoken

2 cars with this same problem, no one can tell me what it is, I am going insane.

If it is detonation, surely the knock sensor would detect it? Should I try replacing the knock sensor?

Midnight Mystery

You have done a good job checking stuff. I honestly don't know at this point., but I'm not very educated at mechanical problems.

Have you poked around with a stethoscope yet?

whitetiger5

It sounds like you're driving the car in the audio, does the engine make the same sound when stationary and just stepping on the gas?

In the video I hear a knocking that increases with speed/frequency. If you're saying it only occurs "under load" you mean it's while driving in gear, correct? what happens if you bring the car up to speed and shift to a higher gear? does the sound still occur the same way? i.e with engine speed? or is it road speed dependent?

Karanx7

iTrader: (2)

I would check your timing belt tensioner.

keantoken

I can't replicate the sound at idle, that is the main reason I don't get anything with the stethoscope. I am considering revving the engine with the parking brake on, it would test the engine mounts at the same time. I haven't wanted to rev the engine up because I guess I'm just afraid it will blow apart or something.

The sound mainly seems to depend on engine load. If I am going up a hill for instance the noise will occur at a lower RPM. The noise does not change after shifts, it follows the engine noise.

keantoken

I cautiously revved to 1000RPM with the parking break on and didn't hear the sound. I think the next thing to try will be to hold down the brake at 20-30MPH to see if that affects the noise.

whitetiger5

“The noise does not change after shifts, it follows the engine noise”

I don’t understand this. If the sound didn’t change after shifts, it wouldn’t be following the engines noise”

does the knocking slow down in frequency with every upshift?

Are you sure it’s not drivetrain related?

keantoken

Sorry, communication error. The knocking follows the RPM, not the wheel speed. It rarely shifts in the middle of knocking so not sure about how it responds to the transmission. Playing with a synthesizer if I put a knock at every 6th bump on a bass wave the sound closely resembles the knocking of the engine.

Today I checked the fuel pressure without hooking up the fuel rail, so I was only testing the fuel one-way valve. I did not get it to leak pressure a single time. So my theory about the one way valve seems wrong. So a leaking injector is back on the table, although I never really found any evidence of that. So I suspect the pressure regulator. Either that or my fuel pressure kit is flaky (which it is). Or even another crackpot conspiracy theory, the 60PSI fuel pressure without the fuel rail along with the sudden pressure release of my gauge busted off some crud in the valve. I will not worry too much about this until I have run some cleaners through the tank and there is still an issue.

The pigeon cooing noise comes from inside the timing cover and gets louder when I remove the inspection plugs. It sounds like a pigeon because it is randomly interrupted. Increasing RPM makes it a bit louder then it goes away as RPM increases. Can someone else record the sound next to the open front inspection plug when the plug is out? The interrupted tone here may indicate a tension problem.

If that is the case then it's possible the tensioner has only just begun to fail. But I would like to hear another timing belt noise to compare.

And of course none of this is sure to be the cause of the knock.

Karanx7

iTrader: (2)

It doesn't sound like a misfire or a knock. It sounds like a bad tensioner or a spun bearing.

Karanx7

iTrader: (2)

Here's a video of confirmed rod knock on an Acura TL

keantoken

The sound is very similar, but I can't get it to happen at idle. Maybe it just hasn't gotten bad enough yet? It it possible there could just be a slow progression with really worn bearings?

I bought this car knowing I was willing to change the rod bearings if it came to it.

keantoken

What I mean is, I can't get it to happen while parked.

keantoken

If however it is a spark knock due to poor injector spray pattern, should I try B12 or Techron first?

keantoken

I discovered the 3rd plug on the lower timing cover, I guess I need to look in there...

Midnight Mystery

The video is kind of a pre-knock scenario.

In other words... the jackhammer is on it's way. You can hear the slight woodpecker style tapping. On my Camry, without much warning, that woodpecker went into all out jackhammer.



Basically sounded like this.

zeta

iTrader: (1)

I can hear it.
I wonder, is that a secondary development, as a result of your two tooth timing jump, after the tint shop visit?

keantoken

So I guess i will try and see what the tensioner is doing through the 3rd timing cover plug, and is there is nothing going on there I will prepare to remove the oilpan and replace the rod bearings. Hopefully this will eventually explain the spark voltage on cylinder number 4.

What would you suggest to replace the rod bearings? Assembly lube? I didn't find a rod bearing DIY on this forum.

Karanx7

iTrader: (2)

You know, I'm not really sure. The motor ran great for 1k miles before the tint shop visit. Then it started with the ticking noise very shortly after. My theory is that some idiot dumped the clutch with his foot still on the brake and it stalled the crank hard enough to jump timing as well as make contact with a bearing. Or it could have been the cheap DNJ bearings I used in the original build. Either way, I polished up the crank and rods and replaced the bearings with OEM parts. No problems since.

keantoken

One of the OEM bearings is discontinued. I have the Mahle/Clevite set in my cart.

Was the spark plug affected on the cylinder with the spun bearing? IE did it look different from the others?

What did you use to polish the bearings? Did you take the whole engine out?