Have an 03 Magna that in going to need the valve stem seals done. Mixed opinions amongst mechanic and stuff I have read off the web whether or not the head needs to be removed to replace the valve stem seals, has any one had any experience with this? Some hydraulic lifter clatter on cold start up as well so thinking of getting this issue addressed at the same time.

PS Can anyone recomned a good mechanic to do this work, in Sydney

Its a pain in the butt to do stem seals on third gen with heads on although it is possible, just need to find someone who done work on 3rd gens before. PM madmagna (Mal) he will give you an idea how difficult it is & how to do it best.

People seem to be saying that it is easier and possibly cheaper to swap for a lower milage motor than do stem seals.
How many k's you got on it mate? What oil you running?
I would suggest before you go doing your seals to change to a thicker oil. If you are currently blowing a little smoke after idle then i would suggest Penrite HPR 30. I have this running in my AWD that was blowing s little smoke after sitting at lights when running Castrol Magnatec and now after changing to the Penrite, it blows no smoke at all.

http://www.penriteoil.com.au/products/motor-oil/hpr/hpr_30

On that clatter at cold startup, there's a common problem with the accessory or AC belt having low tension that causes this. Retention and it's sweet apparently.
I've been meaning to do this, but haven't got round to it yet.
Hopefully this is what yours is and it will save some $ for you.

Thanks for tip on the oil. Currently running Penrite HPR 15w60 changed to this after running with castrol magnatec for years. Still uses alot of oil between services you can smell that it is burning it. It has done about 143k i have owned it since it had 30k always had it serviced regularly.

The clatter on cold start up does not occur every morning for some reason. I had the AC belt done last service and it has clattered on cold start up since so unfortuantly for me the AC belt was not the problem

Thanks for tip on the oil. Currently running Penrite HPR 15w60 changed to this after running with castrol magnatec for years. Still uses alot of oil between services you can smell that it is burning it. It has done about 143k i have owned it since it had 30k always had it serviced regularly.

The clatter on cold start up does not occur every morning for some reason. I had the AC belt done last service and it has clattered on cold start up since so unfortuantly for me the AC belt was not the problem

I think I've come across other posts on AMC that suggest the hydraulic tensioner for the timing belt can also be a source of startup clatter. However if you had it replaced when the timing belt was done, its not likely to be an issue.

As far as your AC belt goes, double check the tension anyway.

I think I've come across other posts on AMC that suggest the hydraulic tensioner for the timing belt can also be a source of startup clatter. However if you had it replaced when the timing belt was done, its not likely to be an issue.



Unless it was not set right at the time of belt change. Have had this happen before.


Try the HPR30 before you do anything else. It will help as i'm sure the 15 did over the magnatec but obviously won't solve the problem.
Mine sounds exactly like yours. With Magnatec was blowing visible smoke after sitting at lights.
Now with HPR30, it doesnt blow any more smoke at all, but you can ever so slightly still smell it burning, but no where near as bad as it was.Oil consumption has slowed but still uses more than it should. This is about all we can do till we do our 3.8 conversions.

Bit drastic, swapping out a motor just because the stem seals are stuffed - unless its a high Km motor. An engine sitting around at the wreckers can have hardened valve stem seals that go smoky quickly despite low km. Heads come off easily on the 3.5 if you don't want to do it heads on. With the heads off its a perfect time to get valves and valve seats checked/reground/replaced and change over the hydraulic lifters. Good chance to set the timing belt up properly and check water pump, idlers and hydraulic tensioner.

Just my 2c worth.

Have looked into this a bit and it is usually similar or cheaper to change/swap a motor for a low milage one or spend a little and upgrade to a 3.8.

Its just me I guess. I would prefer to have my motor with new stem seals, rather than another motor with unknown history. If you get a motor from a car close to the 100,000 km mark, you are still in need of doing the cam belt anyway.

As a DIY proposition, the head work including stem seals and cam belt work is quite cheap.

Then again, if your engine has done 250,000 KM +, and you can find a low km replacement, and need to pay for labour, its worth doing the swap.

Agree with MadMax - "I would prefer to have my motor with new stem seals, rather than another motor with unknown history." So I've committed and ordered the parts from the US.

Is there a mechanic out there (Sydney) experienced in the job who would like the work???? ( I think I would be biting off a "bit" more than I can chew :()

PM me if there is.

Thanks

Doing the seals in a 24 valve motor is neither cheap or easy. The assembly alone is vastly different to that of the 12v motors, and the amout of work on the heads is also a lot more complicated as well

It really depends on the miles your car has, seems some of the TJ's are beginning to get this issue, I am wondering of there was not a change in the seals for the later TJ's given this seems to be coming up a bit now

As for parts for an S4 motor, I will only use genuine parts, will not be bothered to go to all the effort and expense to take it all apart only to save a couple hundred bucks and get inferior parts

Not sure parts will be inferior - valve stem seals that harden & crack after 100kks are not too flash! (I would not replace with MM parts there)

It's looking grim on the mechanic front though. Ordered the overhead valve spring compressor last night & some strong magnets.

May enlist the old man to give me a hand. :)

Where did you order your parts from in the US?

I presume you are going to do the hydraulic lifters too? All 24 or just the failing noisy ones? (there are threads by Madmagna how to test). I believe there are 2 different versions of lifters that will fit, the earlier ones are the same as the 2nd gen 12 valve engine used and the were also used in earlier 3rd gens 6G74s, the later version has more holes 3 vs 1 or 2 I think and are supposed to work better. I believe they are $10-12 each so it adds up.

Not sure parts will be inferior - valve stem seals that harden & crack after 100kks are not too flash! (I would not replace with MM parts there)

It's looking grim on the mechanic front though. Ordered the overhead valve spring compressor last night & some strong magnets.

May enlist the old man to give me a hand. :)

Sorry mate, you can not blame a factory part when you can not say for sure that the issue is not caused by poor service history etc. I know that there have been a couple TJ's of late I have seen with this issue however 1 had 380 cams installed, this will mean valve is opening further onto an area that has previously been gummed up, another has been over 40k with no service so in both of these situations there is a reason. Given the amout of TJ's I wreck alone with good motors with well over 100k on them then I would not point at Mits, perhaps may have bene a bad batch made, with the volume made would not surprise me

I have just seen nightmares with aftermarket gasket kits on these engines

Will be curious if the OHV tool you have purchased can access the springs, if it can would be good if you can let us know what tool you ordered as I am yet to find one that can get in the small gap and grip the springs

Ishrub, I will be replacing all adjusters & stem seals. Have ordered:
99-04 3.5 MITSUBISHI MONTERO SPORT TOPLINE LIFTERS 6G74 (HY-LIFT JOHNSON LIFTERS #ALA MI-4H)
97-02 MITSUBISHI MONTERO DIAMANTE HEAD GASKET SET 6G74 (their part # EH279E1)
from Cnsautoparts (ebay US) total ~ $200 delivered

Madmagna, I got the following compressor:
VALVE SPRING COMPRESSOR UNIVERSAL OVERHEAD AMPRO NEW!!
c_tools_plus (ebay local) ~$35 delivered

Will let you all know how I get on.