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I will be changing the valve cover gasket on my 1998 ML320. Does any know the torque specs for the bolts?
 

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2002 honda civic (sold), 2009 Mercedes ML350
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I dont have the specs, but it isnt high, its around 8 NM or so. but I have done so many of them that I never torque them. I use a 1/4 ratchet and tighten them untill tight. never had one leak or return. and a word of advice, reseal the tops of the covers, that is what usually causes the leaks. the tops are sealed with MB silicone.
 

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'07 C280 4matic, '06 530i, '98 ML320
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I am about to replace the valve covers on my '98 ML320 next weekend. Rather than opening a new thread, I thought I would post my question on this related thread...

I have couple of new "Hi-Temp red RTV sealant" tubes. Can I use this sealant for Valve cover gasket job? I already bought the valve cover gaskets.

I never replaced the valve covers; hence, my novice question: Is it necessary to use the sealant? If so, the sealant should be put only on the top (valve cover edge) only?
 

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I am about to replace the valve covers on my '98 ML320 next weekend. Rather than opening a new thread, I thought I would post my question on this related thread...

I have couple of new "Hi-Temp red RTV sealant" tubes. Can I use this sealant for Valve cover gasket job? I already bought the valve cover gaskets.

I never replaced the valve covers; hence, my novice question: Is it necessary to use the sealant? If so, the sealant should be put only on the top (valve cover edge) only?
Sealant is used to reseal upper breather chambers/oil separators. Part number 003 989 98 20 10. That stuff is thick and stays in place when applied. Don't put anything on valve cover gasket.
 

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ML320 2002
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pcy, why are you replacing the valve covers?

if you will open the valve covers, open the ventilation chambers on top and clean them too. check the cranckcase ventilation hoses and replace if it is hardened and brittle. Use the MB sealant only, not the over the counter stuff.

do not overtighten aluminum screws. they will break.

make sure the gasket and all surfaces are clean and dry before putting the valve cover back on.
 

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'07 C280 4matic, '06 530i, '98 ML320
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Sealant is used to reseal upper breather chambers/oil separators. Part number 003 989 98 20 10. That stuff is thick and stays in place when applied. Don't put anything on valve cover gasket.
Witek, in the post #2 above, streetglower was suggesting to the original poster to use the sealant. That is why I was asking this question. I am glad I asked.

Anyhow, per your suggestion, I will not use any sealant. I will just clean up the area and put the valve cover gasket and carefully tighten the bolts.

Thanks for your feedback.
 

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'07 C280 4matic, '06 530i, '98 ML320
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pcy, why are you replacing the valve covers?
if you will open the valve covers, open the ventilation chambers on top and clean them too. check the cranckcase ventilation hoses and replace if it is hardened and brittle. Use the MB sealant only, not the over the counter stuff.
do not overtighten aluminum screws. they will break.
make sure the gasket and all surfaces are clean and dry before putting the valve cover back on.
Oil is leaking from the valve cover gaskets. Hence, I am trying to replace the valve cover gaskets.

I had already cleaned the ventilation chambers about 6 months ago because oil was leaking from the area where the ventilation chambers were attached to the valve covers.

Thanks for your feedback and advice about not overtightening the aluminum screws.

I expected to see lot more screws holding the valve cover. I only saw 4 bolts per side.
 

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There was a note on the post below that may be helpful..

http://www.benzworld.org/forums/w163-m-class/1465231-mercedes-repair-maintainance-transmission-etc-tips.html

AC


"One other issue on The M112 and M113 engine is that the oil baffles at the top of the valve covers seep oil, changing the valve cover gaskets alone won't stop the oil seep. The reason it appears in this section is that if usually occurs after 5 years on on most of these vehicles the plugs also need to be replaced. If you can replace the plugs and reseal the valve covers the labor is reduced substantially. The seep, when it gets bad, covers the coils and wires in oil and dirt and although it can be cleaned up its something that can be avoided if you inspect the valve covers for the need or resealing at the same the plugs are replaced. The oil baffles on the valve covers are resealed with engine sealant 003 989 98 20 10, its the RTV type sealant that is used for most Mercedes engine assemblies that have no gaskets. This is an outstanding sealant that forms a very strong bond when fully cured, has a 10min work time and skins over quickly so it can be put into service within 30min. It takes awhile to fully cure but that is unimportant to its sealing qualities. Be aware it is critical that the surfaces to be bonded be cleaned of all old adhesive and dirt or any oil. Any oil and the finished assembly will leak."
 

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Keep looking. There are 9 per side.
ahhh. Found them. Thanks.
One last question - I looked in the EPC. Not all 9 bolts have the same part number. Look at the picture below (from EPC). On the left side, 6 bolts have the same part number and the remaining 3 bolts have different part number. What's the difference? Length of the bolts?
 

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ahhh. Found them. Thanks.
One last question - I looked in the EPC. Not all 9 bolts have the same part number. Look at the picture below (from EPC). On the left side, 6 bolts have the same part number and the remaining 3 bolts have different part number. What's the difference? Length of the bolts?
Yes, center bolts go through the baffles and much longer in size.
 

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Thanks,
Can I assume the 430 V8 is the same ?
Can you clean hole with a wire etc. and not remove the cover ?
I suppose you can insert a wire and clean the breathing/ventilation hole. But, the sludge inside the baffle will soon clog up that tiny hole. So, the right way to fix it is by removing it and cleaning the baffles. It's not that difficult. I've done it. Cleaning takes more time than anything else.
 

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There was a note on the post below that may be helpful..

Mercedes Repair/Maintainance Transmission, etc... Tips

AC


"One other issue on The M112 and M113 engine is that the oil baffles at the top of the valve covers seep oil, changing the valve cover gaskets alone won't stop the oil seep. The reason it appears in this section is that if usually occurs after 5 years on on most of these vehicles the plugs also need to be replaced. If you can replace the plugs and reseal the valve covers the labor is reduced substantially. The seep, when it gets bad, covers the coils and wires in oil and dirt and although it can be cleaned up its something that can be avoided if you inspect the valve covers for the need or resealing at the same the plugs are replaced. The oil baffles on the valve covers are resealed with engine sealant 003 989 98 20 10, its the RTV type sealant that is used for most Mercedes engine assemblies that have no gaskets. This is an outstanding sealant that forms a very strong bond when fully cured, has a 10min work time and skins over quickly so it can be put into service within 30min. It takes awhile to fully cure but that is unimportant to its sealing qualities. Be aware it is critical that the surfaces to be bonded be cleaned of all old adhesive and dirt or any oil. Any oil and the finished assembly will leak."
Here it is May 2020 and I am pointed back by fellow members to this thread. I have a 2006 ML500 W164 with the M113 engine. ANd it eats oil like crazy(probably 1 litre every 600- 700kms) - no leaks below. It's going out the tail pipe, puffs on start up kms= 207,000. SO I am looking to do this valve cover cleaning. Is there no PCV Pressure Control Valves to replace? Just cleaning? ANd then when putting the valve covers back on - clean surfaces, and engine sealant on some components ? that maybe mate to the valve cover?
 
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