Honda Prelude Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter #1
This tapping, ticking driving me crazy...
It sounds like an Alien mating call when I'm hard on the throttle.
I have a 99 and in the book it says I have the spring type.



I have reason to believe it may be my LMA, not sure if its just one or a few.
My questions:


Is there a way for me to test and confirm the LMAs are bad?
I was thinking by jumping vtec to engage fulltime, the tapping should go away if LMA is culprit. wondering if its safe to run vtec fulltime. Ive tried to hear the noise at normal vtec but engine and exhaust levels are too dominant.



What causes LMAs to go bad and can they be serviced (clean, stretched, shimmed) and be used again or should be replaced only. That being said, will replacement actually fix the noises.




If you've heard an engine with confirmed bad LMA, please describe
 

·
Registered
Joined
·
13 Posts
Have you checked your valve lash first? It's an old school thing, but you have to adjust your valve lash on these engines.

Sent from my SM-G965U using Tapatalk
 

·
Super Moderator
Joined
·
6,361 Posts
You cannot technically run VTEC full time since you would need to have the oil pressure and higher RPM to engage it.

Most H series motors have a tic - it's normal. If yours is abnormally loud, I would check the valve lash as mentioned above. Nothing to service besides replacing them altogether. I have a complete set for my 01 sitting for my rebuild, there really isn't much to them.

Directly from Honda:

"Remove the lost motion assembly from the cylinder head and inspect it. Pushing it gently with the finger will cause it to compress slightly. Increasing the force on it will cause it to compress further. If the lost motion assembly does not move smoothly, replace it."
 

·
Registered
Joined
·
28 Posts
Discussion Starter #4 (Edited)
Have you checked your valve lash first? It's an old school thing, but you have to adjust your valve lash on these engines.

Sent from my SM-G965U using Tapatalk
Yeah I went over them twice, its a PIA without the jam nut tool.
You cannot technically run VTEC full time since you would need to have the oil pressure and higher RPM to engage it.

Most H series motors have a tic - it's normal. If yours is abnormally loud, I would check the valve lash as mentioned above. Nothing to service besides replacing them altogether. I have a complete set for my 01 sitting for my rebuild, there really isn't much to them.

Directly from Honda:

"Remove the lost motion assembly from the cylinder head and inspect it. Pushing it gently with the finger will cause it to compress slightly. Increasing the force on it will cause it to compress further. If the lost motion assembly does not move smoothly, replace it."
I've always thought that the vtec solenoid opens the valve allowing oil through the passage for engagement upon 12v signal. ill look into that a bit more. And on that note, Ive always thought oil pressure was gauged in binary (either yes or no) so how does the ecu read pressure levels...

Its not a tick, initially I thought it was a rod knock, piston slap sorta deal. Although I havent definitively ruled those out, I'd imagine the sound or symptoms would get worse after...2-3 months.

a clip of it while troubleshooting and some more details with the story:

Few things I want to add, Compression tests were identical mid 190s with one cyl +5 slightly above the rest. I noticed chatter marks on all the lobes on both cams, not sure if or how it can be related. Imagine a shadow line straight across the 3 lobes:
 

·
Registered
Joined
·
28 Posts
Discussion Starter #5
im starting to think its not the LMA. its hopeless, im hopeless. i should just give up and just enjoy the last 11 days with my car.
 

·
Registered
Joined
·
6 Posts
im starting to think its not the LMA. its hopeless, im hopeless. i should just give up and just enjoy the last 11 days with my car.
so you have confirmed that your valves are correctly adjusted correctly right? have you taken it for a good drive and checked if the noise is still present after? I had a tick like that, well sort of like that, and I adjusted my valves to spec and started the car and it was still present. Once I took the car for a ride and got it properly warmed up however, the noise was gone. When I start it cold I still get a tick.
This is going to sound really really old school, but have you tried putting your ear to a screwdriver and listening to various places on the head to see where it sounds louder? Another thing to consider, are you sure your engine wasn't replaced with an engine with the earlier style LMAs? I went through the same questions you are going through when I got mine, to finally come to the conclusion, that the noise was my valves, and that they are still noisy when cold.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #7
so you have confirmed that your valves are correctly adjusted correctly right? have you taken it for a good drive and checked if the noise is still present after? I had a tick like that, well sort of like that, and I adjusted my valves to spec and started the car and it was still present. Once I took the car for a ride and got it properly warmed up however, the noise was gone. When I start it cold I still get a tick.
This is going to sound really really old school, but have you tried putting your ear to a screwdriver and listening to various places on the head to see where it sounds louder? Another thing to consider, are you sure your engine wasn't replaced with an engine with the earlier style LMAs? I went through the same questions you are going through when I got mine, to finally come to the conclusion, that the noise was my valves, and that they are still noisy when cold.
Just a few days ago I came across a few videos about broken/cracked flywheels. Im damn certain this is what I have.
Given the symptoms and test results (process of elimination) and the fact that I've been driving for a few months and the effects has not changed for worse or better, it has to be the flywheel.
Yeah I tried to listen with my long pry bar and it was inconclusive. you see one of the odd things I found was that when I disconnected each spark plug, there was no difference across the board. While this doesnt mean its not a bearing problem, it does mean its most likely not a rod bearing. My LMA's (1999) are the spring type and I checked them all by pushing them down, they felt normal and they werent sticky. Its a good thing I recently found the cause of the noise cuz I put in a few orders from Honda and other local shops to pursue the VI. Now that I know its the flywheel, it's not possible for me to do everything.

But either way though, im still shit out of luck because a cop wrote me up for a vehicle inspection (this was before the noise issue) and I spoke to Honda and they said in order to pass the DOT inspection, I would have to put everything back to stock plus a few things like cv axles, engine mount, rack n pinion boot needs to be done. I have one week left with my prelude and im out of work. I cant be responsible for what I do next because I have to do what I have to do in order to survive. Had this VI not come into play, I would be able to get the repairs done and live a normal life.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #8
so you have confirmed that your valves are correctly adjusted correctly right? have you taken it for a good drive and checked if the noise is still present after? I had a tick like that, well sort of like that, and I adjusted my valves to spec and started the car and it was still present. Once I took the car for a ride and got it properly warmed up however, the noise was gone. When I start it cold I still get a tick.
This is going to sound really really old school, but have you tried putting your ear to a screwdriver and listening to various places on the head to see where it sounds louder? Another thing to consider, are you sure your engine wasn't replaced with an engine with the earlier style LMAs? I went through the same questions you are going through when I got mine, to finally come to the conclusion, that the noise was my valves, and that they are still noisy when cold.
Btw, what was the issue with your valves? I had a good test result from compression test, all cyl were identical between 190-200s.
 
1 - 8 of 8 Posts
Top