engine noise...please advise

[1991q45]

okay after doing the injectors she runs good.infact the car has been pretty good.

but there's is this noise...like a chatter/tapping sound.seems to come from the top front to the middle of the pass. side bank.

before she used to do it alot.now she only does it at certain rpms.

i've been reading up on this and seen some people used marvel mystery oil.

how much do you pour in and has it helped?

[maxnix]

Not too much 8 0z. and change oil soon afterwards.

Might be better to use BG Quick Clean for engines before your next oil change and then use high detergent oils in short OCI cycles.

[unknown007]

mine does the same thing but I just left it as is.Let me know if it goes away.

[1991q45]

yea...but when i first got her it was real bad.

i think one of the problems is the fact i used 5w30.so now i'm gonna use 8 oz. how soon after should i change the oil?

i'm gonna puor some in today and then change the oil either later today or tomarrow

[maxnix]

MMO is a very light machine oil and won't last long.

Depends on weather, engine wear (tolerances), and driving cycles. Do it right before you change your oil.

5W-30 synthetic shouldn't hurt it, but I prefer a 10W-30 synthetic or even 0W-40 synthetic. Fresh in specification oil is always the best oil.

[1991q45]

uhh...yea i dont think it helped.at first i thought it made it worst becuase she was pretty noisy.

but after the mobil 1 10w30 oil change she was pretty quiet.

so i went to autozone to look up timing chain guides (just for s n g's plus i had to get rid of the old oil) correct me if im wrong but i seen the laft and right side pressure guides, the oil guide assembly, the left right slack side.then there's the top ones...so i'm assuming this is right where the cam sprockets are?

i'm asking becuase no one here has had any noise comeing from the vtc assembly, i know for sure the guides has been done, but the noise is RIGHT in front in the cam area...which makes me belive that the "top" guide is worn.

[1991q45]

bump...please

[maxnix]

which makes me belive that the "top" guide is worn.

If you look at EM-10 in the FSM, you will see there is no top guide between the camshafts as the space is so small. There are slack and tension side guides.

Maybe your car's previous owner didn't replace the tensioners? There are halfway timing chain guide replacements, then there are the proper timing chain guide replacements.

[1991q45]

oh no they've been replaced...well it shows on the receipt. it has been said that only the driver side tends to fail. so either they only replaced the driver side. or either the tensioner is'nt getting enough oil pressure to keep tension on it.

but that would apply if it sound like chain rattle

[Infinitiguy19]

OK Check for:

Exhaust leaks Intake leaks/Vacuum leaksidler pulley bearingsInjectors

And there might even be more but that should keep you busy.

[1991q45]

checked all of that.like i said this sound is coming from the pass. side top around the vtc area.

[Infinitiguy19]

Might want to take a look at this: http://docs.google.com/filevie...hl=en

If you want anymore info on the Q45 let me know.

Do you have a laptop Consult?

Does this stop when the engine is fully warmed up?

Between what RPM range does this occur?