Head gasket questions/concerns

#1

Hello Everyone,

I have a scenario and some questions for you all.

At the last Summit event, I had an issue that I had never seen before (not that I’ve seen a lot. I’m definitely considered a newbie). I had what seemed to be water being pushed out of the cooling system through the overflow along with some higher than normal temps. Well, when I came in I had several people look at it and everyone said that I had a head gasket problem and it was pushing exhaust gas into the cooling system. I’m not familiar with that so I took their word and parked the car (Luckily I had a 318 available to finish the weekend in TT).

So I just got around to pulling things apart. I didn’t notice any oil in the cooling system or vice versa. I pulled the head off and I don’t see anything glaringly obvious. Keep in mind I am new to this so I’m not exactly sure what I’m looking for.

So here is my question. I have the head off so what is the smartest thing to do now? Should I send to a local machine shop to be tested or should I ship out to one of the jedi mechanics on the forum to check out?

Question 2. If there is nothing wrong with the head, does that mean something is wrong with the block?

Question 3. Is there something I need to do with the block before I start reassembling? I wish I could go to MM with Ranger!

Question 4. Does anyone have a laundry list of parts/gaskets to replace while I have the head off? Brand names are helpful. I’ve seen conflicting data on head gaskets and bolts. I just want peace of mind.

Thanks for any help. I know it must get tiring to hold the hand of us new guys. I promise to pay it forward when I’m not a dummy anymore.

Jason

#2

Jason,

I’ll try my best…

First off - it would have been easier if the head was still installed. Sometimes a pressure test of the cooling system will reveal a head gasket issue. However, sometimes a problem will not be duplicated with a pressure test… Definitive test can be done with the cooling water. Tests kits are available that will detect when combustion gases have entered -leaked past the head gasket - into the cooling system.

If it were me I would try to get my hands on a test kit or find a shop that will test a water sample out of your car.

I’m suggesting this under the premise that there is no mixing of the coolent & oil. If so, at minimum the head gasket failed. Most likely a cracked head.

Now that the head is off at a minimum you’ll need to have it checked to see if it’s warped. Most would recommend having it surfaced as well. And if you’re going that far might as well have it rebuilt $$$$$ I recently did a refresh of my motor. I did a drip test of the head - search this - and mine was in fantastic condition. Also the head was completely straight. I thoroughly cleaned it up, hand lapped the valves, replaced valve stem seals and reinstalled. So far so good!

As far as head gaskets go, my research indicates the following best to worst; BMW ($$$$), Goetze, and finally Victor Reinz. I ended up using the Goetze. I had a Victor at home and the visible difference between them was significant.

Do some research at E30tech.com regarding proper prep of the block surface and head before you start cleaning them up. Take your time, do your homework, and work in clean environment and you’ll be fine. Everything is pretty straight forward.

Hope it helped!

#3

I agree with PDS’s points.

Exhaust gas putting pressure in coolant is a pretty good sign of a HG issue. Nothing is sure but death and taxes, so it would be nice to have another symptom that confirmed it.

Check the block for flatness with a straight edge.

Re. could problem be in the block. Probably not. It’s more durable than the head.

The head does need to go to a machine shop, even if you don’t do a valve job. It will need to be pressure tested to rule out a crack, checked for flatness and than “surfaced”, which removes a little material from the deck so the HG has a good surface to mate with. This surfacing makes the edges of the holes sharp which is apparently helps the gasket seat.

Get the valve job. This is also the time to check your cam and rockers for wear.

Other things you might do.
–Block off the coolant port at the rear of the head.
–Swap out thermostat for 170deg unit and drill tiny whole at top.
–Put coolant pressure switch in. Best place is probable hose from reservior to radiator.

#4

Thank you guys for the input. How much can I expect to pay for the valve job, test and resurface? Should I send it to a local machine shop or send it to an e30 guru?

Ranger, tell me more about the coolant port at the rear of the head. I’ve never heard that. Has that proven not to cause any issues?

Any suggestions on head bolts?

Thanks

#5

Definitely have the head checked for cracks and warp. If there is warp (a likely case) it will need to be surfaced. What else to do is a matter of budget and expectations. At a minimum I’d do valve seals and grind. If budget allows and you want all that motor can produce, I’d replace all of the exhaust valves, install new guides, match the springs (replacing weak ones as needed), blue print the cam, and replace any worn rockers.

The symptoms you encountered on track were almost certainly from a leaking head gasket, so pulling the head was the right thing to do.

#6

If it makes you feel better, I was having the same issue and no coolant /oil mixing.(Over heating and coolant being pressurized.) I tried to go one more event and then I had Oil in the coolant and massive overheating.

Costs can very greatly depending on what you need/want. I would say on the low end your looking at 350-500 if your keeping all your old parts. I easily have $1000 in to my head now with all the machining, new cam, new rockers and valve guides. Looking back I think i would have rather just paid someone to take care of it all, than doing alot of the work myself. or I should have just bought a known good used head.

My head was decked, but I went with a stock thickness HG from Goetez. I am not sure it is related, but I now have a mystery tapping sound. On VR makes a thinker HG and I want to stay clear of them.
I am currently 3000 miles away from my car, so I can’t try to fix it.

#7

Is there anything I need to do with the block while I have everything apart?

I sent Chuck an email to see what he charges. I think I will feel more comfortable sending it to someone that knows E30 instead of Billy Bobs machine shop down the road.

Jason

#8

Jason, just check the block for straightness. When reassembling everything, make sure it is surgically clean, totally scraped of all gasket material, etc. If you are just cutting the head and doing a valve job, any competent machine shop in your area can do the job. If you are doing a complete rebuilt, I’d recommend someone that knows the head well. Setting valve lash is really important, check on the forum for proper procedure on that. I think I run .010 intake and exhaust, others tighten that up a bit.

A full head rebuild can set you back $1,000. When I put a rebuilt head on my car, it was like I had a whole new engine. I guarantee I found 15 more horsepower. The old head was 180,000 miles old and had never been rebuilt.

#9

jls8177 wrote:

I’m comfortable that blocking the rear coolant port is safe in terms of cooling and smart in terms of eliminating a hose. After loosing an engine to a failed hose, I’m big on eliminating coolant hoses.

We thrashed this about in the forums here about a year ago, looking hard and coolant flow charts. In the end there was consensus that blocking the rear coolant port doesn’t impact engine cooling. It’s real purpose is to provide hot water to the heater before the thermostat opens.

Jim@MetricMechanic agrees too.

Re. headbolts. There’s a number of aftermarket solutions, but unless you plan on doing a lot of head removals, I’d just go with OEM. Shop around a bit and buy a couple sets of them for $18 or better. Get a couple HG’s too, in case that effort goes awry.

#10

What do you guys figure on periodic head re-tightening?

I’ve read several times that this is a maintenance and tuning step highly advised.

#11

Head bolts are torque to yield. Once tightened, leave them alone as you will damage them. I use Race Ware bolts and other than their instructions to re-torque after warming the motor, I leave them alone. Chuck

#12

kgobey wrote:

[quote]What do you guys figure on periodic head re-tightening?

I’ve read several times that this is a maintenance and tuning step highly advised.[/quote]
I’ve not read of folks advocating this outside of turbo guys that have some extreme ideas about headbolt torque.

That being said, if someone had concerns for some reason that a bolt might have loosened, you could check them with a wrench set at 45ftlbs. I did some testing on what you get with the 22ftlbs 90 90 protocol and I’d have to check my notes to see the exact number, but it was under 50ftlbs.

At some point around 50ftlbs, the bolts are twisting, not turning. And when a TTY bolt starts doing that, it’ll twist around and snap before the torque value goes up any. Consider also that our torque wrenches aren’t all that accurate.

#13

Ranger wrote:

[quote]That being said, if someone had concerns for some reason that a bolt might have loosened, you could check them with a wrench set at 45ftlbs. I did some testing on what you get with the 22ftlbs 90 90 protocol and I’d have to check my notes to see the exact number, but it was under 50ftlbs.

At some point around 50ftlbs, the bolts are twisting, not turning. And when a TTY bolt starts doing that, it’ll twist around and snap before the torque value goes up any. Consider also that our torque wrenches aren’t all that accurate.[/quote]

I take this back. I checked my notes and they have a vy high value that makes me suspicious. I’ll have to do this test again.

#14

Is a Felpro gasket good quality? They have a kit with everything in it that looks inviting?

#15

jls8177 wrote:

Opinions differ on this. I’d go with a Goetz HG. There’s some consensus that OEM BMW HG’s are particularly good, but they are very expensive.

#16

Thanks for your help Ranger. I ordered the Goetz. I may be in touch when it comes time to put the head back on.

Don’t know if you remember, I’m the one with the “work truck” (white f350) with the flat bed and work boxes on the back. We talked about the merits of buying a truck like that and then putting a regular box on it because the trucks sell for cheaper. I have to tell you, I went through the process and it worked out great. I ended up selling the flat bed and boxes for a $1,000 profit over the cost of the regular bed. It took some time and elbow grease to change the beds but it worked out in the end. So I ended up paying 10K for a 99 crew cab lariat diesel with less than 100,000 miles.

#17

jls8177 wrote:

[quote]
Don’t know if you remember, I’m the one with the “work truck” (white f350) with the flat bed and work boxes on the back. We talked about the merits of buying a truck like that and then putting a regular box on it because the trucks sell for cheaper. I have to tell you, I went through the process and it worked out great. I ended up selling the flat bed and boxes for a $1,000 profit over the cost of the regular bed. It took some time and elbow grease to change the beds but it worked out in the end. So I ended up paying 10K for a 99 crew cab lariat diesel with less than 100,000 miles.[/quote]

That’s good info. One of these days we’re going to have a better “resources & tips” section here. We’ll have to create a subforum on towing for ideas like this.