question about a knock/noise.need help/advise

[tjvjr]

96 2.5 V6 - 131k .sorry for another one of these questions but i have read quiet a bit and would like confirmation. recently i noticed a knock at about 2300 - 2400 rpms. it is most audible near the timing cover/intake. my first thought was hla but they sound normal at idol. now i am thinking it is the timing belt tensioner but it is hard to tell. what has me confused is the knock gets quieter past 2400 and there is no noise at idol. the guy i bought the car from said he just replaced the timing belt ( old one was in the trunk ) and head gaskets. he did not replace the intake gasket ( it has a bad vacuum leak ) or the valve cover gaskets. this has me thinking that he probably didn't replace the other timing components either. is this normal for a bad tensioner or do you think i have a bad hla? i would think if it is a hla that it would be noisy from idol to high rpm or clear up some of the time. the car needs a knock sensor so my plan is to replace the intake gasket and valve cover gaskets when i install the sensor. should i go ahead and remove the timing cover and check/replace the tensioner ? i guess i should so i know weather or not to replace hlas. whats your opinion? i have heard the hlas can be rebuilt , what does this consist of ? i plan to keep this car for a while but i don't have a great deal of money but will borrow it to make sure it is right. thanks all for any help/advise/opinions.

 

[JKPgt96]

Tensioners on the KL suck. Period. I have gone through several, however, I think that is due to me having the car apart all of the time. So yes..its possible that you have a bad tensioner. That will certainly cause a 'knocking' noise. Take a long screwdriver and place the metal end on the motor in various spots. Then place your ear on the plastic end and listen while the car runs. That is a good way to trace where the noise is coming from.

 

[tjvjr]

found some bad news today. i had changed the fluids and flushed the radiator , things you do when you get a car with unknown maintenance schedule and shortly there after noise got worse , oil started coming into the water and it started missing. i did a compression test and here were the results -rear head - #1 50 , #3 35 ,#5 56. front head - #2 80 #4 60 #6 70 . the front seal started leaking as well. now i am not so sure a head gasket job was done at all , it may have been , idk. from the looks of it additives were in the oil and coolant system. plan now is to pull motor & trans. i have a 94 engine (137k) and although it has a leaking head gasket it was super quiet and strong so i will probably rebuild it or the engine that's in it (131k) , whichever one looks best when i tear them down. it will give me a chance to replace the clutch as well and maybe find a light weight flywheel. what amazes me is how strong this engine was with the low compression .

 

[JKPgt96]

Sorry to hear it. That said..rebuilding these motors is really not very hard. And doesn't cost an arm and a leg.

 

[tjvjr]

yea , Good Lord willing i will get it , i just finished a kl rebuild in the 94 626. just curious , what are the differences in 96 & 94 engines? i noticed there is a 4 0r 5 hp difference ( no bug deal ). i guess it is the added cats and obdII.