Blew a headgasket but same problem!

[///M3weee...]

Though this may not be FI specific thread, the problem is seen here more than others so I figure I post here not to mention I am turboed.

I blew a headgasket from my SPAL fan not turning on all the time and had the head decked, new gasket, yada yada. The mechanic did some tests before he gave me the car back and noticed that there was steam coming from the oil cap (hole). He thinks that I may have a cracked block specifically on the wall that separates the water port and oil port. I no longer overheat and water temps are steady 199 during freeway driving and during city driving, the car is not overheating but the upper radiator hose is hard after driving.

I find that a crack in my block is very unlikely but not out of the question since there are many other circumstances that are more likely for steam to come out of my oil cap (hole). How thick is the wall between the water and oil ports anways? Enough for a crack to form?

A cracked head may be more likely no? I have overheated with this head three times total (once with turbo) and all three times needed decking. Is it possible to have a cracked head and the mechanic to not notice it with the naked eye as well as the machinist? I guess if the machinist is commissioned to just deck the head, he may not be looking for a cracked head.

What are your thoughts and the most cost effective way to solve this problem?

[SiGmA]

No smart mechanic will slap an overheated BMW head back on without having it pressure tested. They often crack internally, and you will not be able to see the crack. This happened to my friends M50 last fall.

[zak]

The radiator hose should be hard for awhile after driving because the coolant system is still hot. I would think you have a much better chance of harming the head rather than the block. I would agree that 3 overheats and so much head work would point to the head being cracked rather than the block mysteriously cracking.

[///M3weee...]

Originally Posted by zak

The radiator hose should be hard for awhile after driving because the coolant system is still hot. I would think you have a much better chance of harming the head rather than the block. I would agree that 3 overheats and so much head work would point to the head being cracked rather than the block mysteriously cracking.

I didn't know that the radiator hose is hard after driving I thought that it should never be hard for this is a sign of pressure going into the heating system. When should it soften up?

Originally Posted by SiGmA

No smart mechanic will slap an overheated BMW head back on without having it pressure tested. They often crack internally, and you will not be able to see the crack. This happened to my friends M50 last fall.

I had the head pressure tested and everything was OK. Maybe the head is cracked internally, but would an internally cracked head cause coolant steam to come out of my oil cap hole?

[SiGmA]

The hard hose is 100% normal. If you want to know if it is NOT normal, you have to hook up a pressure gauge. If pressure spikes under boost, you have a problem. It should soften up a few hours after shutting off the motor, once the motor cools down.

If the head was pressure tested, it won't be cracked. I am not positive on how a machinist pressure tests a head, but my friends was cracked inside the valve port, not on the face at all, and they found it w/ the valves installed. It was not visible until you saw it leaking either. So its doubtful you have a crack.

I suppose it is possible to have a cracked block, tho you would be one of the first I've heard of in the BMW community. Are you positive its coolant steam? A small amount of smoke is normal. If its smoke and not steam, a leakdown will tell you how your rings are, but its not something I'd spend too much time worrying about if the car runs correctly. Its too expensive to worry about lol.

[///M3weee...]

Originally Posted by SiGmA

The hard hose is 100% normal. If you want to know if it is NOT normal, you have to hook up a pressure gauge. If pressure spikes under boost, you have a problem. It should soften up a few hours after shutting off the motor, once the motor cools down.

If the head was pressure tested, it won't be cracked. I am not positive on how a machinist pressure tests a head, but my friends was cracked inside the valve port, not on the face at all, and they found it w/ the valves installed. It was not visible until you saw it leaking either. So its doubtful you have a crack.

I suppose it is possible to have a cracked block, tho you would be one of the first I've heard of in the BMW community. Are you positive its coolant steam? A small amount of smoke is normal. If its smoke and not steam, a leakdown will tell you how your rings are, but its not something I'd spend too much time worrying about if the car runs correctly. Its too expensive to worry about lol.

When isn't the radiator hose supposed to be hard?

I will have it taken to another shop to get a second opinion. The mechanic who worked on my car said he smelled coolant steam from my oil cap hole and said that he'd have to pull the entire motor to see if there is a crack in the block, which I really really doubt.

I drove the car on a warm LA day for about 3 hours and car's water temp which I monitor through a PLX DM200 via the factory OBD2 port (so accurate and fluctuation every few seconds) and the temps were fine.

[SiGmA]

It shouldn't be hard a few hours (especially the following morning) after driving, and prior to being hot. The system will have 5~7psi in it after it gets warm, and that can easily make the hose hard.

You know what, your best bet is to take an oil sample and send it in to Blackstone when you change the oil next. Make sure to get the oil nice and hot first. They will be able to detect coolant.

[///M3weee...]

Originally Posted by SiGmA

It shouldn't be hard a few hours (especially the following morning) after driving, and prior to being hot. The system will have 5~7psi in it after it gets warm, and that can easily make the hose hard.

You know what, your best bet is to take an oil sample and send it in to Blackstone when you change the oil next. Make sure to get the oil nice and hot first. They will be able to detect coolant.

Is there another alternative? I say this because I saw residue in the coolant tank and there may have been some residue on the walls of the tank when the system was drained. Even if they added new coolant, the residue most likely is still there unless they cleaned the inside of the tank.

I have a feeling that there really isn't anything seriously wrong with my car anymore really. There aren't any symptoms of overheating nor a cracked block. I will check to see how much "steam" really is coming out. A little vapor will be present under the valve cover anyway.

[s52e368]

Originally Posted by ///M3weee...

The mechanic did some tests before he gave me the car back and noticed that there was steam coming from the oil cap (hole)

alot ? where are you located and whats your climate ?
could just be moisture.

you could do a few things IMO.

try adding a catch can and see if it helps cut back on the stem, see if your re-circulator valve has any coolant in it from blow by.

monitor your coolant levels closely and see if you find yourself adding to it.

might also consider a means to monitor your coolant pressure.

do you have heads studs? the undercut ones tend to loosen, mine did and blew the hg.

[SiGmA]

Carl makes good points.

I would monitor the quantity of oil/residue in the coolant. Maybe drain the coolant, take a hose to the radiator inlet and coolant hose going from the expansion tank to the engine, and flush it with some fresh garden water.. Then drain as much as possible (block drain) and throw in coolant and distilled water...

I'd first just keep an eye on things, and take a sample when you do an oil change (or sooner if you are really worried). A cracked block is -so- unlikely... And one hell of an expensive undertaking.

[BadBoostedBmwM3]

Originally Posted by SiGmA

It shouldn't be hard a few hours (especially the following morning) after driving, and prior to being hot. The system will have 5~7psi in it after it gets warm, and that can easily make the hose hard.

You know what, your best bet is to take an oil sample and send it in to Blackstone when you change the oil next. Make sure to get the oil nice and hot first. They will be able to detect coolant.

Roman, I thought the coolant system works on a lot more pressure??


Anyways, OP the top radiator hose should be soft by the next morning when you go to start the car.

[m3saloon]

OP please read ~ i have very simmilar issues (if you want to call them that)
1~ I had oil residue in my coolent tank, i jumped the gun and though blown head gasket, this was only after 800 or so miles of first start. I now believe that the oil i had was from when i removed the head. * oil from the head fell into the coolent passages in the block. sat there until a few heat cycles went by it made its way through the radiator and ended up floating on top of my coolent jug.* I've since removed just the oil from the jug (not flushing the entire system) and almost none has come back **one or two pen tip sized bubbles only**
2~ I have steem from the crank case. it actually almost filled my catch can with water/oil residue in 1800-2k miles. More water than oil. In my case it is not coolent in the oil it is jsut H2O from blow by gasses past my rings. I have low compression in 2 cylinders and this extra blow by causes extra crank case vapors. (do a complete leak down test to varify this i would bet you also have warn rings)
3~ the radiator hose should be quite hard with a properly working cooling system. If you take a touchless thermometer and shoot the out side of your alum thermostat cover (where the top hose connects) it should read roughly 230*-250*F leaving the engine when the fan turnes on assuming you have a low temptaure switch installed.
the lower hose where it connects to the housing should read about 180*F when the fan turns on. this is because the temp switch reads the temp of the coolent after it passes through the radiator.

sounds to me like your jumping the gun like i was. GL though either way I hope its nothing cracked.

[///M3weee...]

Originally Posted by SiGmA

Carl makes good points.

I would monitor the quantity of oil/residue in the coolant. Maybe drain the coolant, take a hose to the radiator inlet and coolant hose going from the expansion tank to the engine, and flush it with some fresh garden water.. Then drain as much as possible (block drain) and throw in coolant and distilled water...

I'd first just keep an eye on things, and take a sample when you do an oil change (or sooner if you are really worried). A cracked block is -so- unlikely... And one hell of an expensive undertaking.

I agree that a cracked block is very unlikely and will just keep an eye on things.

Originally Posted by m3saloon

OP please read ~ i have very simmilar issues (if you want to call them that)
1~ I had oil residue in my coolent tank, i jumped the gun and though blown head gasket, this was only after 800 or so miles of first start. I now believe that the oil i had was from when i removed the head. * oil from the head fell into the coolent passages in the block. sat there until a few heat cycles went by it made its way through the radiator and ended up floating on top of my coolent jug.* I've since removed just the oil from the jug (not flushing the entire system) and almost none has come back **one or two pen tip sized bubbles only**
2~ I have steem from the crank case. it actually almost filled my catch can with water/oil residue in 1800-2k miles. More water than oil. In my case it is not coolent in the oil it is jsut H2O from blow by gasses past my rings. I have low compression in 2 cylinders and this extra blow by causes extra crank case vapors. (do a complete leak down test to varify this i would bet you also have warn rings)
3~ the radiator hose should be quite hard with a properly working cooling system. If you take a touchless thermometer and shoot the out side of your alum thermostat cover (where the top hose connects) it should read roughly 230*-250*F leaving the engine when the fan turnes on assuming you have a low temptaure switch installed.
the lower hose where it connects to the housing should read about 180*F when the fan turns on. this is because the temp switch reads the temp of the coolent after it passes through the radiator.

sounds to me like your jumping the gun like i was. GL though either way I hope its nothing cracked.

I doubt that I have the same issues as you but your issue makes me think twice of what's really going on with mine. My motor is rebuilt and have less than 20K on motor and had a compression test and came out strong. I'll def check the temps of everything I can in the motor.

Originally Posted by s52e368

alot ? where are you located and whats your climate ?
could just be moisture.

you could do a few things IMO.

try adding a catch can and see if it helps cut back on the stem, see if your re-circulator valve has any coolant in it from blow by.

monitor your coolant levels closely and see if you find yourself adding to it.

might also consider a means to monitor your coolant pressure.

do you have heads studs? the undercut ones tend to loosen, mine did and blew the hg.

There isn't really that much steam coming out but the fact the my mechanic told me that he could smell coolant worries me especially after he had the head pressure checked and gasket replaced.

I'm in LA where it has been warm and cool recently and somewhat humid.

Right now my crankcase vent it from the side of the VANOS and going out to atmosphere.

I had the old ARP's when I overheated and now the 2000's.

[SiGmA]

Originally Posted by m3saloon

OP please read ~ i have very simmilar issues (if you want to call them that)
3~ the radiator hose should be quite hard with a properly working cooling system. If you take a touchless thermometer and shoot the out side of your alum thermostat cover (where the top hose connects) it should read roughly 230*-250*F leaving the engine when the fan turnes on assuming you have a low temptaure switch installed.
the lower hose where it connects to the housing should read about 180*F when the fan turns on. this is because the temp switch reads the temp of the coolent after it passes through the radiator.

sounds to me like your jumping the gun like i was. GL though either way I hope its nothing cracked.

I agree that jumping the gun is probably happening. I STRONGLY disagree with those temps! A street car should not see over 220*F. I see 180-190*F at idle. 180-200*F at cruise, depending on temps. The OP lives in LA so it could be a little higher. Considering I have a 80*C tstat (176*F) I would be damn worried if I idled at 230*F! Stock temp is 88*C/190*F.

Originally Posted by BadBoostedBmwM3

Roman, I thought the coolant system works on a lot more pressure??


Anyways, OP the top radiator hose should be soft by the next morning when you go to start the car.

I found a post from one guy stating he sees 5-8psi, and more after boosting. I only test NA cars, and usually see 5~7psi. Its not digital tho, so precision isn't 100%.

Originally Posted by ///M3weee...

I agree that a cracked block is very unlikely and will just keep an eye on things.

I doubt that I have the same issues as you but your issue makes me think twice of what's really going on with mine. My motor is rebuilt and have less than 20K on motor and had a compression test and came out strong. I'll def check the temps of everything I can in the motor.

There isn't really that much steam coming out but the fact the my mechanic told me that he could smell coolant worries me especially after he had the head pressure checked and gasket replaced.

I'm in LA where it has been warm and cool recently and somewhat humid.

Right now my crankcase vent it from the side of the VANOS and going out to atmosphere.

I had the old ARP's when I overheated and now the 2000's.

I'd vent your crankcase to a container of some sort. A pop bottle works, lol, or a nice catch can. Then you can see how much moisture accumulates and it might keep your motor less messy.

[s52e368]

Originally Posted by ///M3weee...

I agree that a cracked block is very unlikely and will just keep an eye on things.



I doubt that I have the same issues as you but your issue makes me think twice of what's really going on with mine. My motor is rebuilt and have less than 20K on motor and had a compression test and came out strong. I'll def check the temps of everything I can in the motor.



There isn't really that much steam coming out but the fact the my mechanic told me that he could smell coolant worries me especially after he had the head pressure checked and gasket replaced.

I'm in LA where it has been warm and cool recently and somewhat humid.

Right now my crankcase vent it from the side of the VANOS and going out to atmosphere.

I had the old ARP's when I overheated and now the 2000's.

alot of cars engines retain moisture internally. which could cause the stem. cause primarily catch that condensation more than oil. the odor he smelt couldve been residual from the blown hg prior, sounds like he might be trying to get more work..

several people have mentioned ideas, try something.

[///M3weee...]

Originally Posted by s52e368

alot of cars engines retain moisture internally. which could cause the stem. cause primarily catch that condensation more than oil. the odor he smelt couldve been residual from the blown hg prior, sounds like he might be trying to get more work..

several people have mentioned ideas, try something.

I'm going to do everything people have mention and thank you guys for the insight.

Interesting about him trying to get more work because that's the first thing I thought when he said I might have a cracked block. He also said that he would have to completely take a part my motor to figure out the problem was.

[s52e368]

Originally Posted by ///M3weee...

I'm going to do everything people have mention and thank you guys for the insight.

Interesting about him trying to get more work because that's the first thing I thought when he said I might have a cracked block. He also said that he would have to completely take a part my motor to figure out the problem was.

cool, report back your findings.


wouldnt be the first time some mech. has tried to pull a fast one.

[m3saloon]

Originally Posted by SiGmA

I agree that jumping the gun is probably happening. I STRONGLY disagree with those temps! A street car should not see over 220*F. I see 180-190*F at idle. 180-200*F at cruise, depending on temps. The OP lives in LA so it could be a little higher. Considering I have a 80*C tstat (176*F) I would be damn worried if I idled at 230*F! Stock temp is 88*C/190*F.I found a post from one guy stating he sees 5-8psi, and more after boosting. I only test NA cars, and usually see 5~7psi. Its not digital tho, so precision isn't 100%.I'd vent your crankcase to a container of some sort. A pop bottle works, lol, or a nice catch can. Then you can see how much moisture accumulates and it might keep your motor less messy.

Well i've got the stock fan removed and a 3200cfm eletric in place with a 80*c temp switch, 176*tstat, upgraded wp, and factory radiator. when tested (70ish *F day @ idle after hw run) The coolent temp right as it leaves the engine went up to 230*F and it was 176*F entering the engine at the point where the eletric fan kicked on. while cruseing the upper hose temp didnt go above 200*F at all. Is there a reason why bmw put the temp switch on the cold side of the radiator?

[///M3weee...]

I have an PLX devices DM 200 which plugs into the factory OBD2 port and reads my water temps.

Where would the sensor be located for the ECU to read the water temp?

The reason why I ask is because depending on where the sensor is located you will get different temp readings and in stop and go traffic on the street, I see 220 and that's when my SPAL kicks in.

Where would you want to monitor the water temp as well (going into the motor or coming out)?

[m3saloon]

From my understanding you would want to motonitor the cyl head temp itself, the h2o temp is just easyer for us to tap into i guess. As far as what is better to monitor i'm not so sure

[.Tom.]

I vote no on a cracked block. James told me about your concerns and I personally think that your car is fine, and that you should deffinatly go to another mechanic.

[SiGmA]

I monitor coolant temp in the head, at a sensor next to the DME sensor. They are located under the intake manifold on the side of the head.