r/R53 • u/Intelligent-Car6029 • 2d ago
Time for a head replacement
TLDR: has anyone removed and replaced encoder head themselves and are there special tools needed.
I am getting a cyl 3 misfire code on a 2004 . Starts up a bit rough then runs great and normal speeds and still makes plenty of power. Tried replacing plugs, new coil pack, swapped injectors, finally took it to the dealer and they said most likely it is a bad exhaust valve or seat. At first the tech said new engine but service advisor said need to pull the cyl head and either replace or send it to the machine shop. They want way more than the car is worth to do the repair.
How hard is it to pull the cylinder head and are special tools required? It seems like I can get a new head for about $1000 which would be worth it. The labor at a shop or dealership seems like it is prohibitively expensive.
Has anyone done this?
Thanks all for such a great group of enthusiasts!
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u/Oddman76 2d ago edited 2d ago
Before you try anything drastic check tmap and map sensors. Cylinder 3 misfire was fixed on mine with bad tmap sensor. If not that then do compression test and leak down test it could be a burnt valve. However on to the head I have also recently got a cylinder 1 misfire this is a due to my piston rings Head off was fairly easy there is a video on you tube by mod mini . Head gasket replacement video It's excellent and you can't got wrong if you follow it step by step and will get you to where you need to be. I've had the head off twice now and no issues after.it can also be done without any special tools which I do but would be recommended to use them if you want to be sure to keep timing.
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u/Happy_Ishtar 2d ago
Modmini YouTube channel is your friend, helped me a ton when I did mine: https://youtu.be/WD90wXDTPUs
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u/gdl_E46 2d ago
It's going to come down to what you need to time it. Those will be your specialty tools.. the rest is BMW likes to use etorx for head bolts but this is a Chrysler hybrid so might get lucky there but not expensive...
Before you pull the head it would be worth doing a leak down check to see if it's a valve or ring issue... The suspect cylinder will be leaking air into the crankcase (rings) or into the intake/exhaust (valves) if you can verify a valve problem that'll make the labor to pull the head worthwhile...
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u/Intelligent-Car6029 2d ago
Any links or instructions for the leak down test? I would hate to do the head and then have it be something else.
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u/No-Runnotfun 2d ago
Before you pull the head, please have a look at the Cam, mine had similar symptoms to yours, found cam lobe on the exhaust for Cyl 1 to have damage, swapped with stock Cam and she is all fixed!
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u/Professional_Bike336 2d ago
Replaced my head last year after finding cracks in the spark plug threads. Got a remanufactured one on eBay and it was great.
Be prepared for the job spinning up. I ended up replacing the harmonic balancer, timing chain and other bits during the process
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u/noodlesandsam 2d ago
Did you do a compression test - get that first. If you are not losing coolant or oil, get it tested. You have a P0303 code - what else ?
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u/Intelligent-Car6029 2d ago
Only the p0303 error. Dealership did a compression test and said no compression on 3 supposedly. It still runs fine most of the time just stumbles at start sometimes and it gets a rough idle if sitting to long. Keeping revs above 1200 seems to keep the stumble from happening at idle
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u/Oddman76 2d ago edited 2d ago
If they did a compression test and no compression then do a leak down test to find out if it's rings or valves buylt i'm going to go with burnt valve.By the way you have have cylinder 3 at top dead center so valves are closed when doing the leak down .either way you will soon find out as no compression is head off anyway. Just go have a look at the mod mini videos on YouTube and follow his guide and you can't really go wrong . Even I'm not a professional mechanic and found it easy.
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u/dwtechsol 2d ago
https://waymotorworks.com/cam-lock-tool-r50-r52-r53/
This is the only special toll you need. Other than that it's standard tools.
Once the cam is locked and the bolt is out, DO NOT TURN THE ENGINE OVER. The chain will not come off the crank sprocket but you don't need to completely re-time as long as the crank doesn't move.