Got big $ quote for headwork today...what should I do?

[DanH]

Blew my M30 engine headgasket last month (rear exhaust side coolant hole <--> cylinder #6), so I took it apart. Finally, the head made it to the machine shop at the end of last week.

Today I got a quote of $1200 to fix the head. He said the rocker arms and camshaft are worn and need to be replaced, but the head itself is in good shape. Do I really need to have all of that done? Thats more money than a good used engine.

I did not see anything wrong with the parts myself. (I have some pictures I could try to upload later.) It has 242k miles on it. And seemed to be running fine before the headgasket blew.

Any suggestions would be much appreciated!

Thanks,

[Martin in Bellevue]

Find a new machinist. BMA can get rockers, new eccentrics. I've got a good stock camshaft, but I'd suggest a bigger regrind. I went with a 284 from Ireland.

[Kalevera]

For real...I replaced all of my eccentrics two months ago...did bolts, washers, and eccentrics. Parts cost me about $30 in total. Rocker arms might be a bit more expensive, but heck - If the head is flat, why not just do the work yourself? You were brave enough to pull the thing apart, I'm sure you can figure out how to compress valve springs and what not. How well do the valves seat as they are?

best, whit

[SRR2]

What prompted you to replace the eccentrics? Something like flat spots? At what point do you make the decision to replace rather then just turn them? They don't sit right on the top of the valve or something like that?

[JonE]

Boy for $1200 I'd expect new guides, valves, springs, keepers, seats reground, head planed and everything, maybe even ported and polished! Maybe you could just have it planed and see how it works out. Was it running good before?

[DanH]

Whats the worst that happens if I just resurface the head and re-install into the car with the supposedly bad rockers and camshaft? Break a rocker arm? Lose a few horsepower? Bend valves? Other?

Also, Martin what performance gain did the Ireland 284 regrind get you? How much did the machinist charge to do the work? Mine mentioned something about $600 for the new camshaft, not sure if that included labor. I see Ireland is selling the 284 for $190.

I'll be looking for a new machinist also...although this place has a long reputation. He said most m30 heads are cracked when brought there to be rebuilt.

[Martin in Bellevue]

Worn eccentrics can be hard to set precisely where desired. The eccentric can wear & develop a ridge that the valve tip will ride. Worn eccentrics can make for an either too large or too narrow valve gap.

[DanH]

It was running just fine until the headgasket gave way.

Thats why I dont see why it should be so bad. I think the quote included rocker arms, camshaft, and something about seats being reground, maybe valve guides.


Boy for $1200 I'd expect new guides, valves, springs, keepers, seats reground, head planed and everything, maybe even ported and polished! Maybe you could just have it planed and see how it works out. Was it running good before?

[Martin in Bellevue]

I think my machinist bill was about $400. I got new guides.
The ireland 284 seems to have moved the torque band up the rev range just a bit. The 284 does make charges to 6k rpm more worthwhile. It pulls well.

[DanH]

I dont know how well the valves seat, other than it ran fine... not sure how to check it, thats why its at the machinist.

Compressing valve springs seems to be a tricky job without the proper tools so I dont know about doing that myself.


For real...I replaced all of my eccentrics two months ago...did bolts, washers, and eccentrics. Parts cost me about $30 in total. Rocker arms might be a bit more expensive, but heck - If the head is flat, why not just do the work yourself? You were brave enough to pull the thing apart, I'm sure you can figure out how to compress valve springs and what not. How well do the valves seat as they are?

best, whit

[callen]

Dan:

I didnt touch either of my heads...just cleaned up and new gaskets....both running fine..my 535 has 250K miles on it and 150k on 735il

[JAlfredPrufrock]

Screw that, you started it yourself you may as well keep your money and do a good job, upgrade a few things along the way.

[DanH]

I figured it just needed to be resurfaced too. I'm sure it'll hold up just fine for quite a few thousand more miles.

The guy must be a little short on his next house payment...;-)

The only thing I'm worried about is if it would be in imminent danger of cracking a rocker arm or something. I think that these few engine parts ought last a lot longer yet before really needing replacement.

What about replacement of the valve guide seals? Anyone have an opinion on that?

[Alan_525i]

Here's where you all scream that I paid too much.

$3500 dollars got me a top to bottom new head. Valves, seals, guides, machine work on the ports, reground cam, rockers, shafts, EVERYTHING was new. Also did a radiator, water pump, all hoses, and installed an exhaust. $85 an hour labor rate. The engine runs amazing now though.

[Kalevera]

True - mine had flat spots, which meant that I could tune in a clean .011 or .013, but nothing in between. It was really frustrating the first time I did valves -- it was late, dark, and I began to wonder if something was wrong with me because I couldn't seem to set the sucker right on .012. Add to that manually turning the crank via the alternator (the WRONG way, incidentally) and you got a pissed off Lowell, and it takes a lot to get me angry. The next day, it ran nastily and was quite noisy.

With the new eccentrics, things are much smoother, and it takes about a minute to adjust a valve, versus the 4 or 5 (check - loosen - set - tighten - check X 5) min with the old ones. Plus, replacing the bolts is just a good practice. I have no idea how long it's been since the engine had a head job, and knowing the kind of PO this car had, he probably wouldn't have let the mechanic spend his money on replacing those bolts.

best, whit

[Kalevera]

Yeah, I'd be running in the opposite direction of this machinist. Between the board and your apparent technical facility, I'd say you don't need a machinist. Did you see any scoring on the cam lobes when you pulled the valve cover off?

best, whit

[DanH]

I didnt really notice anything terribly wrong on the cam lobes when I pulled the valve cover. You can definately see where the rocker arms and lobes have been contacting for 242k+ miles, but I figured it seemed not too bad for the age. I had never pulled another valve cover so wouldn't know what to look for as far as bad cams go.

I'm sure a new cam and rockers would improve the engines character a bit but not $1200 worth more.

Right now I think I'll just have him resurface the bottom of the head and then take it home and look it over again.

[DanH]

Update...

I called there again and he said it would be about $625 to put in new exhaust valve guides, drill out and replace a couple of broken exhaust studs(I broke those), resurface the head, and do a valve job on it right now without replacing the camshaft and rocker arms. He claimed there was a good chance it would make more noise without the new parts after the valve job.

And, he said the head is at a different one of their machine shops that does a lot of work for the local BMW dealership. Seems like they must be charging a special BMW labor rate.