Will appreciate very much any suggestions. 94 525i with 197,000 km, auto. trans. When in Park, tapping noise seems to be coming inside the timing chain cover. Mechanic says maybe the timing chain. Drive belt and fan clutch had just been replaced. I bought the car 2 yrs ago and not sure if timing chain was replaced by previous owner. The car otherwise is in good condition and not losing power. Pls comment. Thanks
Tapping noise in timing chain cover when in Park..
- Thread starter carl0422
- Start date
A question and two possibilities:
Does it tap faster as you rev the engine? I assume so...
1. What weight oil are you using? The older engines do not like 5-30 synthetic, it's too thin, and it will cause the VANOS to operate noisly. Check your manual for the proper oil weight,
2. Could be the timing chain tensioner, not the chain itself. Read more here...
Does it tap faster as you rev the engine? I assume so...
1. What weight oil are you using? The older engines do not like 5-30 synthetic, it's too thin, and it will cause the VANOS to operate noisly. Check your manual for the proper oil weight,
2. Could be the timing chain tensioner, not the chain itself. Read more here...
Thanks Kirby. I'd just done an oil changed recently. I'd put in about 1000km since then. I used 5w30 Mobil synthetic as recommended by a bmw tech. Previously I used 15w50. Should I change it back to 15w50 and dumped the still fresh 5w30 (ouch!!$100 down the drain).??? This certainly will be much much cheaper than getting the whole timing chain and the tensioners done, maybe $1200-$1500.. Thanks also for the link, that is very helpful. Anymore advises will be appreciated.
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Yes, the 5w30 is the problem, I know this from first hand personal experience with my '94 325i. 5-30 is OK for the new engines, but the older ones need thicker oil. The VANOS unit has a hydraulic cylinder in it. The thinner oil cannot hold pressure in the cylinder, hence the tapping noise.
10w40 is the recommended oil for this engine, Mobil1 10w40 is available but not so easy to find sometimes. I drained out about half the oil, and added almost 4 quarts of 15w50 to end up at 10w40.
After you do this, the noise will not go away immediately. It will take a week or more for the 5w30 to be completely flushed from the VANOS cylinder. No guarantees, but this worked for me.
10w40 is the recommended oil for this engine, Mobil1 10w40 is available but not so easy to find sometimes. I drained out about half the oil, and added almost 4 quarts of 15w50 to end up at 10w40.
After you do this, the noise will not go away immediately. It will take a week or more for the 5w30 to be completely flushed from the VANOS cylinder. No guarantees, but this worked for me.
Thanks Kirby for the prompt reply. Much appreciated. 15w50 mobil syn. was very hard to find. I went back to specialty auto store where I bought it but none in stock. Anyway, I will do as you suggested and hopefully it will work. I'll keep you posted. I'd like to keep this car as long as I can. It's otherwise in great condition and fun to drive. Regards from Toronto , CAN
Kirby, I pasted this post. Rather interesting.
Inspection II does not inolve changing of the timing chain. That will be a pricey undertaking if you take it to a shop. While the actual act of changing the chain is not really any more difficult than changing a timing belt, it's the design of the E36 engines that make it more difficult to access the chain and hence make the job more labor intensive. The engine simply was not designed with changing the chain in mind.
To answer the initial question - changing oil viscosities/weights will not change the slap. You have worn tensioners and they need to be replaced - changing the oil weight will not fix the problem.
__________________
Justin
2007 Pontiac G5 5-speed
1967 Chevy Camaro SS350
RIP 1987 325e coupe
Inspection II does not inolve changing of the timing chain. That will be a pricey undertaking if you take it to a shop. While the actual act of changing the chain is not really any more difficult than changing a timing belt, it's the design of the E36 engines that make it more difficult to access the chain and hence make the job more labor intensive. The engine simply was not designed with changing the chain in mind.
To answer the initial question - changing oil viscosities/weights will not change the slap. You have worn tensioners and they need to be replaced - changing the oil weight will not fix the problem.
__________________
Justin
2007 Pontiac G5 5-speed
1967 Chevy Camaro SS350
RIP 1987 325e coupe
What Justin says is true - IF the problem is a stretched timing chain or bad tensioners.
On the other hand, if the noise is VANOS low hydraulic pressure due to using an oil thinner than spec, using the correct viscosity will correct the problem. Since you said this occurred shortly after an oil change from 15w50 to 5w30, it's the most likely problem and solution. And I know this solution from personal experience.
Listen carefully to pinpoint the location of the knock. If it is chain tension, it will more likely be BELOW the VANOS bulge on the top of the engine. If it sounds like it is coming from the very top of the engine at the VANOS bulge, it's more likely the pressure issue. If you can put your hand on the bulge and feel the knock, it's almost certainly the pressure issue.
Also, changing the oil is the quickest and cheapest first step in troubleshooting.
On the other hand, if the noise is VANOS low hydraulic pressure due to using an oil thinner than spec, using the correct viscosity will correct the problem. Since you said this occurred shortly after an oil change from 15w50 to 5w30, it's the most likely problem and solution. And I know this solution from personal experience.
Listen carefully to pinpoint the location of the knock. If it is chain tension, it will more likely be BELOW the VANOS bulge on the top of the engine. If it sounds like it is coming from the very top of the engine at the VANOS bulge, it's more likely the pressure issue. If you can put your hand on the bulge and feel the knock, it's almost certainly the pressure issue.
Also, changing the oil is the quickest and cheapest first step in troubleshooting.
Thanks again Kirby. Just had the 5w30 drained out and put in 15w50 instead. I'll keep my fingers crossed and do a process of elimination the cheapest way!! Hopefully it works. As you said it may take up to a week of driving before I find out. Have a great day.
I'm looking for a 92-94 325i auto. Any issues I have to be aware of for this particular year and model.??Thanks
I'm looking for a 92-94 325i auto. Any issues I have to be aware of for this particular year and model.??Thanks
Check this thread