Head gasket job in my future. Any tips?

[DesertBMW]

Well I pulled the head today and looks like the bunghole I purchased this vehicle from lied profusely when he told me it had never overheated.

Why would you believe anything that sellers say? Everybody lies. I got two good 885 cylinder heads for sale here in Phoenix AZ, so you can see and inspect them for yourself, I don't have to say much. Quit believing everything that sellers on ebay say also,

[ForcedFirebird]

.003" transverse and .004" longitudinally is what is in the BMW manual, so you "should" be ok without milling. It sounds like you know your way around a head since you mentioned lapping the valve seats. If you bring the bare head to a machine shop (cleaned prior) they will only charge around $50-100 and you will be 100% certain it's flat and square.

Don't forget to check the top of the head too as if that curve matches the bottom, the cam bores might get a little tight. Many shops skip the heat-straightening and just skim it till it's flat (which will make the piston to head clearance vary from cyl to cyl). If the entire head is warped, it's not a bad repair to do. The head will get bolted to a plate with shims under it, then heated up and slowly cooled.

There are divots on the head that indicate if it's been shaved too far, and if you go past, the domed pistons will hit the head (valve clearance won't be the issue).

Yes, the 885 heads are getting more expensive and rare. Took me several months to compile 8 of them that had never been milled, so I could flow all and hand pick the best for Spec-30 legal engines (head must be 100% stock in the series).

[faber]

.003" transverse and .004" longitudinally is what is in the BMW manual, so you "should" be ok without milling. It sounds like you know your way around a head since you mentioned lapping the valve seats. If you bring the bare head to a machine shop (cleaned prior) they will only charge around $50-100 and you will be 100% certain it's flat and square.

Don't forget to check the top of the head too as if that curve matches the bottom, the cam bores might get a little tight. Many shops skip the heat-straightening and just skim it till it's flat (which will make the piston to head clearance vary from cyl to cyl). If the entire head is warped, it's not a bad repair to do. The head will get bolted to a plate with shims under it, then heated up and slowly cooled.

There are divots on the head that indicate if it's been shaved too far, and if you go past, the domed pistons will hit the head (valve clearance won't be the issue).

Yes, the 885 heads are getting more expensive and rare. Took me several months to compile 8 of them that had never been milled, so I could flow all and hand pick the best for Spec-30 legal engines (head must be 100% stock in the series).

Thanks! It looks like this head has never been milled, there is plenty of meat left according to the milling indicators. I guess it is consistent with what the seller said about the head coming off a runner, I wish he had taken more care in packing it but it looks like it is gonna work. Since I am not gonna rebuild the bottom end I will take the money I had for that work and drop the head off to a machine shop for inspection/rework. Appreciate the insight! It will be interesting to see what the machinist finds.

[apostate]

It is always a common mistake to find a cheap E30 and reckon that it can be restored (or at least brought to a decent condition) for pennies.
Your approach to that car is wrong.
If you have decided that it is too expensive for you to make it a decent ride, better sell it and get some money back.
That, in turn, will save a lot of trouble for you and the car. E30 is a money pit and if you don't have the right mind-set of affection for the model, you will soon discover that you made a huge mistake.
IMO, sell the car.
Cheers.

[faber]

E30 is a money pit and if you don't have the right mind-set of affection for the model, you will soon discover that you made a huge mistake.
IMO, sell the car.
Cheers.

Yup, already figured that one out. I have already put tons of work into this POS. I have no affinity for it other than it is my daughter's first car. Her second car will be much better. That one will be purchased after this E30 dies and is subsequently razed in celebration.

[e30davie]

They are a money pit when compared to initial outlay but in general they are quite cheap to play with if you diy labor.

I had the head on my m20b23 overhauled by my favourite shop. Came back basically new. Including all gaskets and consumables for me to do the job as well as $900 for machine work, cost me about $1500 to bascially redo the top end and almost all external items on the engine.

Some people would pay more than 1500 for a mild service for a modern car.

However they do need constant tinkering which is for someome who likes that, not sure id buy one for someone not all that keen on constant tinkering. Ie a daughter:p

[ForcedFirebird]

It's an awesome car for a daughter. I have a 19yr old and she like the 86es with a b25 swap the best. "It's a sleeper, dad."

EDIT: The son is getting his license soon, but he is more interested in the Exie v10 hauler and wants to tow the e30's.

[faber]

Yeah, I am on the fence at this point. If she showed the slightest interest I would happily restore the car to show car quality. I don't think she really cares much though, so I am not feeling like putting much more than the bare minimum into it from here on out. I got a couple days to think about it before I get back out to the garage anyway. I picked it up for $500 and have put about $800 into it so far. I was figuring on spending $2k on a good running first car for her so I still have some room. Once I have the motor running the only things I have left to correct are some worn suspension parts, a front valance, and aesthetic touch ups.

[ForcedFirebird]

Sounds like you are on a good road to having a fun, practical car for her. Once you get them sorted, they are cheap maintenance. What can you expect from a car going on 30? Better platform and safer than the air cooled Dubs I was driving as a kid. heh

[SDbboy]

If you are installing the head yourself make absolutely sure the head bolt threads are ultra clean, run a tap through them at least twice.

ARP head studs obviously. Don't rush this job, it's easy to mess up. Use good tools, lighting and make sure you have help when you need it.

[faber]

If you are installing the head yourself make absolutely sure the head bolt threads are ultra clean, run a tap through them at least twice.

ARP head studs obviously. Don't rush this job, it's easy to mess up. Use good tools, lighting and make sure you have help when you need it.

Chasing threads is never a bad idea. ARP head studs are overkill for this application though, it is not gonna see any boost, just a daily driver. the stock head bolts lasted 200k+ miles, so a new set will be just fine. I have probably done a couple hundred head gasket jobs so I am comfortable with the job. When I started this thread I was more just looking for common pitfalls, and tips to make the job go quicker since I am not familiar with this particular vehicle. Great advice from everybody though. Really helpful folks here on this board!

[ForcedFirebird]

Stock bolts are fine, even with some boos, for sure.

Couple of m20 tips.

Use a quality head gasket. Elring and VR leak. Goetze is the go to brand, not overly expensive, yet very close to OEM BMW (~$80 for HG alone). Stay away from any gaskets (except Cometic) that have the oval shared hole at the center of the head. FelPro uses Goetze HG in their kits.

Much quicker to use a hoist and remove/replace the whole top end as a unit. Intake, and exhaust manifolds attached. The intake manifold bolts are narrow 12mm to easier fit a socket, but have wave washers that get easily lost when reaching under to remove/install.

Set the head to TDC, set the #1 piston to TDC, then rotate the crank 20° ATDC and all the pistons will be low enough there will be no chance of piston valve contact, then back it up to TDC once the head is fitting (and timed).

When installing an m20 timing belt, it's easy for it to slip on the crank during install since the cog to timing cover clearance is tight to wrap the belt. I generally back the crank up one tooth, and wrap it on the tensioner last. This way, you rotate the crank forward and the tension side will take up slack as you slide the belt over the tensioner pulley. (if that makes sense in words). If you compress the tensioner completely and tighten the mounting screw in the slotted hole, the tensioner will stay out of the way for easy belt install. Replace the tensioner spring and pin that backs up tot he water pump. They are cheap and the spring provides the perfect tension to the belt before you lock the tensioner.

The coolant outlet on the back of the head can be a bear when everything is installed. If the heater is connected, pre-planning on hose clamp fastener orientation can aid in later repairs in that area.

Use mechanic's wire to compress the spring on the "bitch tube" that goes from the crank case to the intake manifold. Stack spring, washer, then o-ring top to bottom, then wrap wire on spring to keep depressed, shove it in the block (spring completely stacked), install top o-ring. This will keep the tube low enough to install/remove the manifold/top end, then cut the wire and the tube will pop up and seal at the manifold. If you forget the tube, it will not go on after the head is seated unless you remove some material from the bottom, or remove the intake from the head.

[faber]

Stock bolts are fine, even with some boos, for sure.

Couple of m20 tips.

Use a quality head gasket. Elring and VR leak. Goetze is the go to brand, not overly expensive, yet very close to OEM BMW (~$80 for HG alone). Stay away from any gaskets (except Cometic) that have the oval shared hole at the center of the head. FelPro uses Goetze HG in their kits.

Much quicker to use a hoist and remove/replace the whole top end as a unit. Intake, and exhaust manifolds attached. The intake manifold bolts are narrow 12mm to easier fit a socket, but have wave washers that get easily lost when reaching under to remove/install.

Set the head to TDC, set the #1 piston to TDC, then rotate the crank 20° ATDC and all the pistons will be low enough there will be no chance of piston valve contact, then back it up to TDC once the head is fitting (and timed).

When installing an m20 timing belt, it's easy for it to slip on the crank during install since the cog to timing cover clearance is tight to wrap the belt. I generally back the crank up one tooth, and wrap it on the tensioner last. This way, you rotate the crank forward and the tension side will take up slack as you slide the belt over the tensioner pulley. (if that makes sense in words). If you compress the tensioner completely and tighten the mounting screw in the slotted hole, the tensioner will stay out of the way for easy belt install. Replace the tensioner spring and pin that backs up tot he water pump. They are cheap and the spring provides the perfect tension to the belt before you lock the tensioner.

The coolant outlet on the back of the head can be a bear when everything is installed. If the heater is connected, pre-planning on hose clamp fastener orientation can aid in later repairs in that area.

Use mechanic's wire to compress the spring on the "bitch tube" that goes from the crank case to the intake manifold. Stack spring, washer, then o-ring top to bottom, then wrap wire on spring to keep depressed, shove it in the block (spring completely stacked), install top o-ring. This will keep the tube low enough to install/remove the manifold/top end, then cut the wire and the tube will pop up and seal at the manifold. If you forget the tube, it will not go on after the head is seated unless you remove some material from the bottom, or remove the intake from the head.

That post is made of gold Sir. Thank you!!!
I did remove the head with the intake and exhaust still attached, I just did it by hand, no hoist. It was awkward, but not as heavy as I expected it to be. Thanks so much for all those tips, that is exactly the kind of stuff I was looking for.

[ForcedFirebird]

I have probably done a couple hundred head gasket jobs so I am comfortable with the job. When I started this thread I was more just looking for common pitfalls, and tips to make the job go quicker since I am not familiar with this particular vehicle. Great advice from everybody though. Really helpful folks here on this board!

That post is made of gold Sir. Thank you!!!
I did remove the head with the intake and exhaust still attached, I just did it by hand, no hoist. It was awkward, but not as heavy as I expected it to be. Thanks so much for all those tips, that is exactly the kind of stuff I was looking for.

No problem. It's enjoyable to pass on this info. I know my kids love the e30, they have been at speed on the race track in them (as well as very quick cars), we volunteer for the "Kids Racing For Life" program here in FL. You get this car sorted, you daughter will be driving to school in an iconic car for her age, it will be reliable and not made of tin foil like modern cars. I have witnessed 9 second e30's that have the stock single ear diff mount, but you buy a modern z3 with 16ga steel and they fall apart with the stock 200whp.

This brave young man had ridden with me for the past few years. Leukemia survivor.

https://www.youtube.com/watch?v=OMmea_3M-Pc&t=90s

[Das Delfin]

don't know what all the negativity in the beginning of this thread was about. This is supposed to be a enthusiast forum with support hello??? Telling the OP to sell his car what a bunch of horse shit

I never had an affinity for old bmw growing up - but I like mine. Hell, it's been more reliable than my old toyota pickup, the car Top Gear deemed the most reliable car... in the world

What makes one of these cars work is DIYing the maintenance. Make it a father-daughter bonding experience!

tips would be use a goatze or elring gasket, and use ARP studs. There is a gasket for a metal coolant hose in the back of the head that is a pain to replace with the head in the car

you wanna update the cam gear and intermediate gear while you're at it