Balance shaft and top end rebuild m272
#1
Balance shaft and top end rebuild m272
Hi
I have just started down the path of pulling down the engine after fault codes of balance shaft and other codes showed up on the dealers scanner he said it would cost $7500 just for the balance shaft and if it required more work it could be more so seeing I bought the car used I was not willing to put that much money into the repair so I decided to take a chance and do it myself.
Here's some photos of what I've done so far
Engine block looks clean <br/>
Valve work to be done
Faulty balance shaft removed
Teeth worn
I have just started down the path of pulling down the engine after fault codes of balance shaft and other codes showed up on the dealers scanner he said it would cost $7500 just for the balance shaft and if it required more work it could be more so seeing I bought the car used I was not willing to put that much money into the repair so I decided to take a chance and do it myself.
Here's some photos of what I've done so far
Engine block looks clean <br/>
Valve work to be done
Faulty balance shaft removed
Teeth worn
#2
G'day
I pulled the valves out today and noticed a lot of oil had been bypassing the stem seals so I ordered 24 new seals and will start on some valve lapping tomorrow
All intake and exhaust vales removed
Valve stem seals removed
Dirty ports with caked on burnt oil
Starting to lap inlet valves
This a ml350 4 matic with 139000 klm
#4
Thanks Mate
As they say a picture says a thousand words so here's some more
Exhaust valve dirty as and not closing
Exhaust valve ready for a clean
Valve cleaned up ok on the wire wheel
Old stem seal and yes I have grease under my nail
Stem seals 6 per packet 4 packet required
New valve stem seals and sleeve
As they say a picture says a thousand words so here's some more
Exhaust valve dirty as and not closing
Exhaust valve ready for a clean
Valve cleaned up ok on the wire wheel
Old stem seal and yes I have grease under my nail
Stem seals 6 per packet 4 packet required
New valve stem seals and sleeve
#5
Senior Member
Join Date: Apr 2012
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2012 ML350 Bluetec, 2015 GL350 Bluetec
Great writeup! I have a 07 R350 that I'm going to do the balance shaft within the next couple weeks. I'm right now trying to gather all materials I need and am looking at the oil pan sealant. WIS calls for Loctite 5970 but I don't know how much is needed? There are 2 packages one 50mL and one 300mL I don't know which one to buy. Did you run into this problem?
#6
G'day
I'm also doing some research on what sealant to use for the timing case and sump to block and oil pan the factory stuff just looks like a rtv silicone sealant that easily wiped of with some degreaser not impressed this engine weeped oil and was dirty all over all from factory so I'm looking for a better sealant if anyone cares to add their two bobs worth I'd be glad to here your suggestions
The most important thing is to follow bead size and sealant paths too much rtv is your worst enemy even the factory silicone was observed partially obstructing oil paths so less is more! Sorry I couldn't help
New rear seal
Balance shaft
Balance shaft kit arrived from you blokes in the states
New shaft
New and old balance shaft
I'm also doing some research on what sealant to use for the timing case and sump to block and oil pan the factory stuff just looks like a rtv silicone sealant that easily wiped of with some degreaser not impressed this engine weeped oil and was dirty all over all from factory so I'm looking for a better sealant if anyone cares to add their two bobs worth I'd be glad to here your suggestions
The most important thing is to follow bead size and sealant paths too much rtv is your worst enemy even the factory silicone was observed partially obstructing oil paths so less is more! Sorry I couldn't help
New rear seal
Balance shaft
Balance shaft kit arrived from you blokes in the states
New shaft
New and old balance shaft
#7
G'day
When pulling down the engine I noticed the inlet manifold vacuum actuator for the flaps had been rubbing on the magnesium body of the manifold on closer inspection I found it was snapped off and hanging freely so I decided to disassemble the pierburg manifold and found a mess of plastic parts free and floating inside, some parts were ingested and were nowhere to be found
Plastic flap snapped
Plastic lever snapped from the location
Inlet manifold
More plastic bits
Inlet manifold dirty with oil and dust mix
If I had parts I could rebuild it but for 500 on eBay I bought a new one
Flap runner broken
When pulling down the engine I noticed the inlet manifold vacuum actuator for the flaps had been rubbing on the magnesium body of the manifold on closer inspection I found it was snapped off and hanging freely so I decided to disassemble the pierburg manifold and found a mess of plastic parts free and floating inside, some parts were ingested and were nowhere to be found
Plastic flap snapped
Plastic lever snapped from the location
Inlet manifold
More plastic bits
Inlet manifold dirty with oil and dust mix
If I had parts I could rebuild it but for 500 on eBay I bought a new one
Flap runner broken
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#9
G'day
Just wondering if anyone has a pic or PDF of the timing cover sealant path as my pic doesn't show it clearly thanks,here's a pic of my new inlet manifold with some of my parts installed
Inlet manifold
Just wondering if anyone has a pic or PDF of the timing cover sealant path as my pic doesn't show it clearly thanks,here's a pic of my new inlet manifold with some of my parts installed
Inlet manifold
#10
G'day
Here's the only pic of the timing cover sealant path and it's not real clear in someone has a better image
This is a screen shot from YouTube I do have the latest epc/wis version but my pentium4 32 bit won't run it <br/>
Here's the only pic of the timing cover sealant path and it's not real clear in someone has a better image
This is a screen shot from YouTube I do have the latest epc/wis version but my pentium4 32 bit won't run it <br/>
#11
Super Member
Geez....they sure aren't making MB like they use to.
The engineering (on the whole line) has suffered so much since the early 90's cars.
It really is a crap shoot now buying a used MB....the same worries (maybe even more) you'd have when buying a used Ford or GM.
Balancing shaft failures....timing chains that stretch...oil coolers in the diesels with seal problems. And these are all hugely expensive repairs.
Why even consider a used MB when a comparably equipped Lexus cost less and is more reliable.
Probably why there are so many Lexus out there driven by really proud owners.
I use to have that feeling about my Mercedes...Pride of Ownership...not any more.
How could the engineers at Mercedes get it so wrong..AGAIN AND AGAIN AND AGAIN?
The engineering (on the whole line) has suffered so much since the early 90's cars.
It really is a crap shoot now buying a used MB....the same worries (maybe even more) you'd have when buying a used Ford or GM.
Balancing shaft failures....timing chains that stretch...oil coolers in the diesels with seal problems. And these are all hugely expensive repairs.
Why even consider a used MB when a comparably equipped Lexus cost less and is more reliable.
Probably why there are so many Lexus out there driven by really proud owners.
I use to have that feeling about my Mercedes...Pride of Ownership...not any more.
How could the engineers at Mercedes get it so wrong..AGAIN AND AGAIN AND AGAIN?
Last edited by Brian McL; 08-18-2015 at 12:31 PM.
#12
G'day
These problems are not engineering design issues they are component quality control issues and yes you would think that when you pay that sort of cash for a Mercedes Benz that they would check components were up to scratch before installing 500,000 plus balance shafts! Its now the iPhone era for Mercedes Benz trade up to the new model every year and the used car customer gets balance shafted!!!
Thanks Joe
Ps. Can any one email me a better pic of the timing cover sealant path
These problems are not engineering design issues they are component quality control issues and yes you would think that when you pay that sort of cash for a Mercedes Benz that they would check components were up to scratch before installing 500,000 plus balance shafts! Its now the iPhone era for Mercedes Benz trade up to the new model every year and the used car customer gets balance shafted!!!
Thanks Joe
Ps. Can any one email me a better pic of the timing cover sealant path
Last edited by Captain.caveman; 08-21-2015 at 07:04 PM.
#13
I have a 2006 ML350 with 127,000 miles. I am in the vin range and as far as I can tell my balance shaft has never been touched. I bought the car at 70k and there is no record of it being done. Can I have the only one that isnt going to fail? Its like driving a ticking time bomb. I tried to sell it but no takers (shocker). Its delegated as a snow car and I drove it 2k last year. Its in perfect condition. Ive fixed so many things that it pushed me to buy a new 4 Runner for my wife. Shes a high miles driver. I drive a LS400 rear drive Lexus with 200k daily. Never breaks.