Why must you replace (or must you) the manifold gasket each time the intake manifold comes off? I have reused mine several times, once when the manifold had to come off a few days after I put the new gasket on and once when I didn't happen to have a new one on hand. There don't seem to be any apparent issues. Will a check engine light come on if the gasket is not sealing properly or are there other hidden problems that could occur like sucking in unfiltered air, poor mileage, etc.?

I do have a new gasket on hand now, but was just wondering. I will be taking my manifold off soon to remove, ream and re-antisieze the glow plugs. It's been a year and a half and after going through one breaking off on me, I'd prefer to take this preventative measure even though I'm not sure that using antisieze is the solution, but it makes me feel better.

Len
'99 E300 DT 99,500 miles

Gaskets are replaced upon reassembly because they crush upon the first assembly. If there were coolant going through that gasket, replacement would certainly be required to prevent leaks.

If you have the turbo motor, air leaking in the manifold may confuse the MAF, causing a MIL. May not though. Anyway, the air leak is probably small to nonexistent given the pressure involved.

Actually, I think you're on to something. I recommend using grease on the gasket when assembling to ease disassembly. If it doesn't tear when you take it apart, use it again if you feel up to it but grease it again. Note that grease has been used on gaskets since their inception. It swells the fibers and helps get a good seal with no bonding.

The gasket I'm talking about is a metal gasket.

Len

I've always replaced the gasket. But not replacing could really save some money as much as we must remove the intake.

I always keep a spare gasket "in stock". I'll continue to replace unless I hear a convincing argument otherwise.

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Neil
1997 E300D - naturally aspirated
280,000 miles (as of November 2015)

I didn't realize that it was metal. These still crush, but grease won't help. I don't think I'd use sealer on it either, but reusing it may still be viable.

I'm sure replacing the gasket every time is overkill, but how do you know how many times is OK without risking having to re-do it because the gasket starts leaking? The OEM gasket only costs about $10-$15...in the grand scheme of things it's not that big a deal to replace it every time the intake is pulled just for good old prevention of a potential problem, IMHO. I've only pulled my intake off twice in 2 years. Each time I replaced it...just to play it safe.

As conservative as I am, I'm not sold on the idea of R&R'ing the GPs just to make sure they aren't seized. I just don't see risking breaking one off for no good reason while just checking them. I say leave them be until it is necessary to replace one.

I also have changed my feelings on replacing them all if one goes bad...now, if one of mine burned out I would simply replace that one and keep driving until the next one needed replacement. I can R&R the intake in about 30-40 minutes and the car will still start on 5 or even fewer good plugs so it is not an emergency if one burns out and I can't get to it immediately.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Its a sheet of metal with holes in. Just use gasket sealant and you'll be fine. Thats what I did.

It is not a flat piece of metal but has ridges around the openings...it's stamped with raised areas.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

606-141-01-80, it's super thin metal with the areas for sealing purposes, simple stamping process, but effective. Oh if I had it off and went back soon, I might even give it another life.

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raMBow

1999 E300DT Obsydian Black Metallic, Heated Full Leather Parchment options, E2, K2, 136,000+, best 36.5 mpg - GP's 12-04 & 11-12 Zero Stuck
2010 Honda Odyssey - The BrideMobile - best 26.5
(2) 2005 Honday Accord- (1 -Corporate 1 - Personal) - 110,000 4-cyl 30mpg
2000 VW Golf GLS TDI, Upsolute Chip (sold to Brother, now 300+k on it) 48.5 mpg like clock work
1987 Honda CRX HF - Sold 87,000 always over 50 mpg Max 67 mpg

Nothing to it.

And do take note, the one for the N/A version of the OM606 is a different gasket, made of a thicker fibre material but looks the same as far as its physical configuration.

I found this out when Fastlane sent me the wrong one by accident but I knew the last time I replaced mine it was thin and metal. They are not interchangeable, but I bet lots of techs and DIYers have put the wrong one on because they didn't know there were 2 different types available.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Why risk an air leak over $10? I mean, if it was a $300 gasket that had to be shipped in from germany, I might think about it but this is ridiculous. Crush washers and gaskets are NOT meant to be used more than once. You crush it and it conforms to the surfaces that are not flat and that produces a seal. Why bother with gooping it for $10?

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01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

I'm not worrying about the $10. Hell, I waste a whole lot more money on parts for the car that another ten bucks isn't going to hurt. There were a couple of times when I either had to or chose to reuse the old gasket like if it was only on for a week or so. What I wanted to know was if there would be any obvious signs like a check engine light if the gasket wasn't sealing like it should.

Len

Whether it goes back on again or in 5 yrs, what difference will it make?

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

Probably not a CEL since the leak would be slight if any. So, if you are in the middle of BFE and wanted to make it work for a week till you got home, that should not be a problem. If it is going to be long term, I wouldn't

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow