noisy hydraulic tappets

JHZR2

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Hi, my car, mentioned in another post (91 BMW 318i, 4cyl M42 engine) has noisy hydraulic tappets. This to me seesm like it would be due to reduced flow. Would a lower viscosity (say the 0w-40 discussed in the other post abouut my car) be better in keeping this from happening? It seems they are noisy any time the car is idling, even when hot. Would this indicate dirty tappets, reducing flow? I think the best bet would be to run autoRX to help clean them, then switch to the 0w-40 for a quick 3mo/3000mi interval, then, assuming no usage, use it permanently, otherwise use either a mix of it and 15w-50 or something else (maybe delvac 1?) Any comments on this idea? I hate the noisy tappets. I have heard that noisy tappets are happy tappets, but Im not happy when the car practically sounds like a diesel because of the tapping noise. Thanks, JMH
 

JHZR2

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After analyzing a bit more, it seems that they are noisier when hot... Maybe this means that they are right about needing 15 or 20w-50! (or the castrol 5w-50 perhaps, although Im not as keen on a high VII group III oil at full group IV price). Any ideas? Thanks JMH
 
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I don't know anything about your engine but have you eliminated mechanical problems or can they be adjusted? If everything is correct I don't see how you can hurt a thing with the Auto RX. Finally try some different oils but they probably can't fix a problem. It seems odd they make noise when they are hot, I usually think of cold temperatures and valve noise.
 
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Hi all, new guy who loves tech stuff. On bimmerforums, bimmerfest, uucdigest list, etc. with an M3 motored 318ti and E30 325. BMWs seem to tick a lot, various cures are fill 1/2 to 1 qt. over for track/autocross, change weights, etc. I'm a heavy tracker/autocrosser, although the ti has an oil cooler and doesn't see north of 220*F much. I've always wondered about the light vs. heavy debate. Pre '96 or so the manuals stipulate 20W-50 for over 20*F, the xW-30s not meant for above 60*F or so, very different from the US/Japanese 5W-30 guidelines. Then BMW reversed course and now specs 5W-30, for the same engines. So which is it? My concerns are of course having cold flow for BMW's tight tolerances but the Amsoil 2000 0W-30 does not meet the A3-B3 spec, although I'm not doubting it's a great oil. The M1 15W-50 currently has consumed 1 qt. so far, will 2000 0W-30 be worse? I may just try it anyway this winter and compare it to the 2000 20W-50 in my other thread. [ May 23, 2003, 01:02 AM: Message edited by: Gary ]
 

JHZR2

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Im thinking to try the M1 0w-40, which is a3/b3 rated, energy conserving, pretty thick at 40degrees, and will flow better than a 15wt oil when cold... Im going to try it sooner or later (see my other post about 0w.40 in a car designed for 15w-40), but maybe after I trya nd fix these tappets... JMH
 
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I agree with the above....get them adjusted. If the adjustment's out, no oil brand will help you with this or any other maintenance issue.
 

MolaKule

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Make sure the engine has been cleaned with one of the cleaners mentioned on the board. Then use Delvac 1. If the condition persists, then the rocker arm nuts will have to be adjusted.
 
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quote:
Originally posted by MolaKule: Make sure the engine has been cleaned with one of the cleaners mentioned on the board. Then use Delvac 1. If the condition persists, then the rocker arm nuts will have to be adjusted.
Interesting. I hadn't even considered the rocker arm nuts.
 
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quote:
Originally posted by cryptokid: get them adjusted and go back to your normal oil.
I may be showing my ignorance here, but I didn't think hydraulic tappets could be adjusted. I thought that was the entire point of hydraulic lifters/tappets, no?
 

MolaKule

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Ray H said something I hadn't thought of as well. Good advice. After putting the oil retainer clips on the rocker arms, and engine running, I prefer to back off the rocker arm nut until the rocker arm clatters, and then torque it down slowly past the point of where the nut was originally. Then back the nut off just to the clatter position again, and then final torque the nut 3/4 to 1 turn after the initial clatter. This "exercises" the hydraulic lifter to position itself at other travels to help it pump and clean itself. I use a 32" caliper to determine orignial position of the nut below the top of the rocker stud. [ May 24, 2003, 01:14 AM: Message edited by: MolaKule ]
 
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Yeah...I don't think they're hydraulic then because a friend of mine needs to get his adjusted on regualar intervals on his 3 series.
 
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I was going to say my 78 320i was not hydraulic. But then again ...neither was the 3.0 6 at that time. I assume that they incorporated some hydraulic lash since the 6 became "the most maintenance free engine in the world" ..or so the ad claimed at one time. They may have done this with the 2.0 (1.8 later). What's funny is, if it is solid lift, it behaves like a hydraulic "no-adjustment" pump up lifter like those in the AMC/DC/JEEP 2.5 and 4.0. That is, there is NO ADJUSTMENT ...you just torque the bolt that holds the rocker arm to 21 ft/lb (or lb/ft to the clowns that changed it after decades of being ft/lbs - probably just to be "chic"). The lifts are somewhat noisy for hydraulics at idle on these engines. This type of set up would behave just as described...better when cold ...noisy when hot
 

JHZR2

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no, mine is the m42 engine (that was tnen put into the newer e36 3-series (and then gotr bored out to 1.9L and put into the z3 1.9, etc. Definitely hydraulic... Maybe Ill give the 'exercising' a try to see if that cleans it. Neutra and a timing chain tensioner will be my first shot, along with 0w-40... Thanks JMH
 
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