ENGINE OUT...QUESTION
11-24-2018, 05:55 PM
#1
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ENGINE OUT...QUESTION
Pulled engine and trans out today, got trans done no issues. If anyone ever thinks about doing one....very easy with basic tools. PM me and I will help. I am a rebuilder by trade.
Started on engine and came across something very strange.Before the heads even came off we saw permatex between the head and block.Pulled heads and saw that indeed there was permatex on the head gaskets....from the factory ! and this engine looks to have never been apart.
Anyone ever see this? I have NEVER seen permatex on any engine in all my years of being a tech but.......this is a Mercedes ! LOL
Started on engine and came across something very strange.Before the heads even came off we saw permatex between the head and block.Pulled heads and saw that indeed there was permatex on the head gaskets....from the factory ! and this engine looks to have never been apart.
Anyone ever see this? I have NEVER seen permatex on any engine in all my years of being a tech but.......this is a Mercedes ! LOL
11-25-2018, 12:12 AM
#3
Haven't verified myself (too lazy), but apparently in the WIS via my Google-Fu it says the following:
Cylinder Head Caution for Mercedes M112 and M113 EnginesSealing surfaces of the crankcase and cylinder heads are provided with an 0.8 mm thick silicone layer (Loctite 5900) during standard factory assembly. Silicone sealant should be applied during repair assembly only if sink holes exist in the sealing area.
My initial thought was that the sealant is just used to keep the head gaskets in place while you mount the heads, but if it's applied all the way around and on both the block and heads, then that wouldn't make sense. Based on the above description though, it sounds like this is only applied at the factory and shouldn't be used during a rebuild (unless there are "sink holes", whatever those are). I've used Loctite 5900 on things like oil pans and oil pump covers on other cars, but I would've never thought to use it on head gasket mating surfaces for any reason. Never seen that either.
My initial thought was that the sealant is just used to keep the head gaskets in place while you mount the heads, but if it's applied all the way around and on both the block and heads, then that wouldn't make sense. Based on the above description though, it sounds like this is only applied at the factory and shouldn't be used during a rebuild (unless there are "sink holes", whatever those are). I've used Loctite 5900 on things like oil pans and oil pump covers on other cars, but I would've never thought to use it on head gasket mating surfaces for any reason. Never seen that either.
11-25-2018, 12:19 AM
#4
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Macedon ...looked at that video and his heads had it as well....missed that the first time.
GM Lover...It is really strange to see silicon on a head gasket but then again when do these ever blow a gasket even with much more boost? It works very well {silicon} I guess !!
GM Lover...It is really strange to see silicon on a head gasket but then again when do these ever blow a gasket even with much more boost? It works very well {silicon} I guess !!
11-25-2018, 01:21 AM
#5
Member
They all have silicone from the factory, but there is no need to replace it when rebuilding unless you notice any irregularities in the surface, which is unlikely (make sure you do a good job cleaning it off, though). Just be sure not to forget the one (or two?) spot on the left side where it is required (per WIS).
11-25-2018, 08:05 AM
#6
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Thanks...Might even look into the Permatex copper spray I used to use on my supercharged Ford engines. Worked well for this type of situation.
Just learry of the fact that the factory used silicon and that was with brand new parts.
The block and and heads look absolutely perfect and clearly with 17lb's of boost the Tune was dead on so it was great to see that !
Just learry of the fact that the factory used silicon and that was with brand new parts.
The block and and heads look absolutely perfect and clearly with 17lb's of boost the Tune was dead on so it was great to see that !
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11-25-2018, 12:23 PM
#9
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