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trying to diagnose noise (injector or LMA)

davidkimchee

davidkimchee

Contributing Member
Joined
19 April 2005
Messages
142
Location
San Jose, CA
Can someone describe what loud injectors sound like?
Can someone describe what sticky LMAs sound like?

Ive searched and am convinced I have the sewing machine ticking from the LMAs but am not 100 percent sure.

If it was a noisy injector would the noise dissapear at a certain point where the injector is always open?

Anyone have success at quieting the LMAs without disassembling the entire head?

david
 
ok for the injectors. If you put your ears close to it, you'll definitly hear the loud kicks.

You can put a straw up against each individual injectors and stick the other end in your ear and listen to them that way.

It will be a consistant click click click noise. I should not be too loud. Over idle engine, you should bearly hear them.

LMA? - im not sure what this stands for. I might be able to help more once i know what your talking about.

And the injectors could stay open.... :biggrin: but thats if you are running a more CC then the injectors can handle + agressive fuel map.
 
LMA=Lost motion assembly

Ill stethoscope my injectors to see if one of thems noisy...but at this point Im pretty sure its the LMA.

Oh how I wish my car didnt sound like a diesel truck.
 
Have you checked the valve lash yet. I gues while you are in there doing that you can check the LMAs, but I have not heard of any known problems related to these assemblies, they are a very simply device and the service manual says to make sure they move smoothly, but does not say much more than that. Other than the pain of getting to them they can be cheap, Acura list two part numbers, I do not know what the difference is but one is 9.65 and the other is 39.40 list. Lets hope if you need them they are the 9.65 ones.

Page 6-36 in the service manual items 15 or 18

Dave
 
Last edited:
LMA's are quite common on the NSX.
They don't go 'faulty', they go sticky. I had a few of them which where replaced from a NSX. When you push them in, they sorta stick for a sec in the down position, and then come up again. I took 1 apart, to see if there was wear or scores, but it looked quiet oke, so i tried cleaning another 'faulty' one with solvent and such, let it dry, put it in oil again, and it works great again.

I remember a post from someone ages ago who just took them LMA's out, and just cleaned them.

Here in EU they list for E42,69 each, doing them all runs upto $750 parts only.

I should have done mine when i had me headgaskets replaced.
 
Maybe we should have replaced them....

Can you say there whas carbon or sludge dirt inside ?? If this is the case than it might be possible too clean without taking apart......
 
Cees-Jan said:
Maybe we should have replaced them....
Click to expand...

Maybe? Pfff, the moment i started that engine i knew i should have replaced them ;)

Cees-Jan said:
Can you say there whas carbon or sludge dirt inside ?? If this is the case than it might be possible too clean without taking apart......
Click to expand...

Thats exactly what i looked for when i took it apart. Didn't see anything like sludge or a thick substance, though i think there was some carbon residue inside.
I'm not sure if you can clean it with engine cleaner, coz it seems they are tucked away really well up in them heads, and cleaning them took quit a while. But hey, why not try....
I do remember though when the guy i have them sticky ones from had them replaced, the engine sounded absolutely completely different (in a good way).
 
I can order in some stuff, it should be added to the engine oil, after this run the engine, do not drive, 3/4 of an hour, replace engine oil and filter.

It makes the oil very thin and has lots of carbon solvents inside, it might clean out.

The brand worked very well on my 465 000 km Legend engine (cleaning hydraulic valve lifters)and on an other occasion at Skoda we "repaired" an engine, Nico, the shop owner allready wanted to take apart engine: Look on the net for Forte automotive products.
 
Yep I think the advanced moto flush will do the job.copy and past from the site:

FORTÉ ADVANCED FORMULA MOTOR FLUSH
Advanced Formula Motor Flush has been specifically formulated to combat modern motoring issues caused by the adverse affect of extended oil drain periods.

During the long interval between oil drains, crankcase acids are produced. If left within the system when the oil is changed, these acids immediately go to work breaking down the new oil leading to the creation of lacquers and varnishes which are deposited on the oil system components such as Hydraulic Valve Lifters, Variable Valve Timing Systems and Piston Rings. These components work within very tight tolerances and any sticking due to the deposits in the oil system results in inefficient operation of the system and poor driveability.

Neutralises crankcase Acids.
Removes lacquer, varnish, sludge and insoluble deposits from the crankcase.
Frees sticking Variable Valve Timing systems, Hydraulic Valve Lifters and Piston Rings.
Stabilises cylinder compression restoring lost engine power.
Cleans engines internally and provides anti-wear protection.
 
Rome was not build in one day......

I ment" stationair draaien drie kwartier en af en toe gas geven, niet gaan rijden omdat de motorolie dunner is geworden en dus geen hoge druk (zoals tidens het rijden) kan verdragen..." But how to translate ...
 
Cees-Jan said:
Rome was not build in one day......

I ment" stationair draaien drie kwartier en af en toe gas geven, niet gaan rijden omdat de motorolie dunner is geworden en dus geen hoge druk (zoals tidens het rijden) kan verdragen..." But how to translate ...
Click to expand...

Idle for 45 minutes, so now and then rev the engine. Do not drive because the engine oil has become very thin, and therefore will not be able to withstand high pressure. "Maar hoe te vertalen"

Still sounds scary............ But them LMA's sound like crap as well.
 
Well translation, sounds scary and in a way it is, this is also the reason why they do not sell to private persons, only ment for use in a workshop where there are people who (pretend to :biggrin: ) know what they are doing....
 

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