OFHG Replacement + Coolant (N55)

[bosstones]

Finally getting around to working on my X1 again. Mainly because of time, I will forego the water pump and t-stat for now and just focus on the OFHG and VC/VCG. I can always curse myself later.

For the OFHG, I plan to clamp the radiator hose that runs to the housing (mine is nice and pliable).

Once everything gets buttoned back up, I'll top off the radiator expansion tank but would I need to run the bleed procedure, too?

None of the DIYs I've found seemed to cover this unless someone drained all the coolant beforehand.

[Gamb1t]

The coolant bleed procedure is easy. Why not run it for peace of mind?
IIRC there will be some coolant spillage when you remove the housing. Be prepared to change oil too if you are fussy about not getting any coolant into the oil passages.

[bosstones]

Originally Posted by Gamb1t

The coolant bleed procedure is easy. Why not run it for peace of mind?
IIRC there will be some coolant spillage when you remove the housing. Be prepared to change oil too if you are fussy about not getting any coolant into the oil passages.

No reason. Just didn't know if it was a step.

I already drained the oil and replaced the plug but didn't add new oil yet. Should I not have? I didn't see anything that indicated otherwise. I expected coolant over the serpentine belt and am prepared for that.

[bosstones]

Self-thread jack....

How the fook does the intake manifold come out?!

I have the throttle body off and all the bolts/nuts (2 and 5, respectively) out, vaccum line disconnected, etc...

I can lift the manifold off from the engine enough to clear the mounting studs but something on the firewall side seems to be preventing it from coming out.

I do not have all 6 electrical connectors disconnected at the connector bank below the manifold, near the firewall since I can't figure out how to disconnect the last, far right one. Without taking that one out, I can't access the right side tabs to disengage the other 2 connectors. It doesn't look like any of the harnessing is in the way, preventing removal of the manifold, though, and I even removed the 2 bolts that I tought held the connector plate to the manifold.

I also disconnected the brace/retainer for the hose that connects to the throttle body.

[Gamb1t]

Think you will get more response at the e90 or e82 forums.
Is there a leak that is traced back to your VCG or OFHG? For the VCG, if it is just minor weeping, you might be better off leave it. Lots of people made it worse after replacement.

[bosstones]

Originally Posted by Gamb1t

Think you will get more response at the e90 or e82 forums.
Is there a leak that is traced back to your VCG or OFHG? For the VCG, if it is just minor weeping, you might be better off leave it. Lots of people made it worse after replacement.

I'm sgetting a little from the OFHG but primarily from the VCG. The dealer confirmed this when I had them resolve the stuck hood latch a few months back. It's enough to grime things up pretty good, with some collection on the plastic underbody cover.

Make it worsge because of improper sealing? Or messing something else up?

Figured out the one connector. The connector retainer is at the base and slides parallel to the plate it connects to.

[Gamb1t]

I just read over at the e90 forums where folks tend to misalign or didn't tighten the screws properly during reinstallation of the VCG leading to exacerbating the leak.
Sure it's not the oil pan, rear main seals etc? IIRC the N5x engines are slant 6, so oil generally deposits will be at the passenger side area.


Leak from the OFHG would cause oil being flung to your drive belt that overtime will deteriorate its integrity leading to belt failure. So I'd tackle that first.

N55 is now an older engine used with in many BMWs. So DIY resources abound. Just not so much in e84 section.

[bosstones]

Originally Posted by Gamb1t

I just read over at the e90 forums where folks tend to misalign or didn't tighten the screws properly during reinstallation of the VCG leading to exacerbating the leak.
Sure it's not the oil pan, rear main seals etc? IIRC the N5x engines are slant 6, so oil generally deposits will be at the passenger side area.


Leak from the OFHG would cause oil being flung to your drive belt that overtime will deteriorate its integrity leading to belt failure. So I'd tackle that first.

N55 is now an older engine used with in many BMWs. So DIY resources abound. Just not so much in e84 section.

That makes sense.

I didn't check the oil pan myself but the dealership tech did when they freed up the hood release a few months back. They confirmed the VCG was my main isse w/ the OFHG starting to show signs of leaking.

I've got all the parts (incl screws and bolts) and torque values for both VC+VCG, ignition coils, spark plugs, OFHG, OFCG, oil cooling line o-rings, etc... It made sense to do these at the same time. I bought a new serpentine belt and pulley kit just in case my OFH was leaking onto them. Thankfully it isn't. The belt is still in good shape so I'll leave it for now.

Yeah, I learned that when trying to get the intake manifold off. I thought I had been thru enough DIY videos and forum postings to cover myself but....no. ShopLifeTV has a good video that actually covered how my problematic connector unlocks. It was in his vid for..I think starter replacement on a 135i.

I'm taking pix and notes as I go so I can eventually write something up.

[bosstones]

Took way too long to do this (OFHG + VC). In part because of being busy (and driving my Moupe instead) but also looking up torque specs, feeling my way around the engine bay, etc...

I still plan to do an E84 write-up since I used a mix of various DIYs but ran into minor things along the way that I'd rather have known going in.

Ran the bleed procedure twice and also did the oil priming procedure since it'd been sitting w/o oil for a bit. Happy to say, the X1 fired up last night!

I did notice some oil dripped on to the exhaust but I could not find trace of any oil seeping out from the VC. The rear of the VC was hard to get a mirror in for inspection but I eventually got it. I also ran my hand around the edges several times and it always came up dry. I'm guessing it was old oil that pooled somewhere from when I removed the old VC and that it dripped out once the engine was running (vibration). I'll keep an eye on it.

[Gamb1t]

Well congratulations! Even better there's no weird codes. Often times people missed putting it together resulting in codes popping up after. Real PITA to trace.

Lots of plumbing and doodads to remove for the VCG work.

[bosstones]

Yeah, I was happy it started right up w/ no codes. Wasn't that rough a start compared to what I expected after having depressurizing the fuel lines.

I'm leaking a little bit of coolant, though. Right now, it seems to be from the hose at the bottom of the expansion tank. Seems like it is fully seated and I don't think I put pressure on it when I put the air duct above it back in.

[bosstones]

Replaced the expansion tank last weekend since I noticed coolant aitting on one of the mounting flanges. Also noticed a glisten along the underside of the seam around the upper part of the expansion tank. I figured it might he the culprit.

While there, I also replaved the overflow hose, upper radiator hose (since I broke the plastic nipple the overflow hose connected to), and mickey mouse flange. Luckily, I had all the parts already and it sense to do them while I had the radiator drained.

Took the car out for a spin tonight and didn't see any coolant leaks! However, I had an occasional stutter if doing more than an easy, graduated acceleration. I pushed it a bit and.....cylinder 5 misfire. All new plugs and coils. D'oh. Since it was tight doing the plugs last time, I'll re-seat #5 and go from there. Still have the old coil packs but no spare plugs other than the old ones.

So close...lol