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Head gasket and bolts question 91 240

durk80

durk80

Member
Joined
Nov 17, 2015
Location
South GA
Hi all, I was wondering if after cleaning out the head bolt holes to keep them from loosening, could one apply thread locker to the treads to keep them in place? I know that you are supposed to just lightly oil them and torque in the correct sequence after carefully cleaning and chasing the threads, yet this will be the second time in the past 5 months that I've had to remove the head for this problem. One bolt seemed not to tighten with new head bolts (felpro).
I had the head tested for leaks, new valve hushers, and planed down, yet I've been getting misfires after sitting, and a milky substance under the cap, and after doing a dye test, verified the leak. The car is a 91 240.

Was I supposed to use rtv sealant to apply to some of the bolt holes in order for the coolant not to mix with the oil? The reason why I ask is because I didn't do this for my 88 240 and it turned out just fine.
 
"* Don't put RTV sealer on the head bolts or holes"

Thanks Otto. I think I was in panic mode when I saw the dye mix with the oil under black light, as it was the same thing that happened before taking the head to the shop except without the dye--the milky fluid under the cap and the loss of coolant with no puddles under the car. I'm hoping that it was my error and that it isn't a minute fissure behind the valve guides, or in the engine block itself.

Thanks again!
 
I assume you followed the spec and tightened them in the correct sequence and then added the quarter turn after torque spec?

Definitely don't use anything other than a light coating of oil. Double check your torque wrench maybe as well? With my ~2ft breaker bar I recall that extra quarter turn was some good solid effort.
 
durk80 said:
Hi all, I was wondering if after cleaning out the head bolt holes to keep them from loosening, could one apply thread locker to the treads to keep them in place? I know that you are supposed to just lightly oil them and torque in the correct sequence after carefully cleaning and chasing the threads, yet this will be the second time in the past 5 months that I've had to remove the head for this problem. One bolt seemed not to tighten with new head bolts (felpro).
I had the head tested for leaks, new valve hushers, and planed down, yet I've been getting misfires after sitting, and a milky substance under the cap, and after doing a dye test, verified the leak. The car is a 91 240.

Was I supposed to use rtv sealant to apply to some of the bolt holes in order for the coolant not to mix with the oil? The reason why I ask is because I didn't do this for my 88 240 and it turned out just fine.
Click to expand...
What do you mean one bolt wouldn't tighten? They all need to be tightened identically.
 
VB242 said:
What do you mean one bolt wouldn't tighten? They all need to be tightened identically.
Click to expand...

I don't know, it just seemed easier to turn the last quarter turn than the other bolts.

I did a compression test today and all cylinders were nearly identical to each other (145 psi) Would this mean there is something else wrong?
 
I mean if you're finding water mixed into the oil you have a problem for sure.

What transmission is in your car? Reason I ask is that on my AW7X the trans cooler ran through the radiator end tank and I had THAT actually break and had me thinking my HG was fubard. Turned out the oil and water in question was the ATF and the coolant.

Are you seeing oil in your coolant or coolant in your oil?
 
EivlEvo said:
I mean if you're finding water mixed into the oil you have a problem for sure.

What transmission is in your car? Reason I ask is that on my AW7X the trans cooler ran through the radiator end tank and I had THAT actually break and had me thinking my HG was fubard. Turned out the oil and water in question was the ATF and the coolant.

Are you seeing oil in your coolant or coolant in your oil?
Click to expand...

Sadly, no. I have the M47. I *think* I am seeing coolant in the oil.

Yet, these are other factors that *could* be part of the car's symptoms.

1. I drive to work 6 days a week, one mile each way.

2. The climate here has been damp and cold in the mornings.

3. The oil smells like gas. (just put in new injectors, didn't chng oil yet)

4. Sometimes there is a slightly milky substance on the oil cap.

5. Cylinder #4's spark plug was sooty and oily. All others were normal in appearance. The valve cover was leaking, but I'm unsure if its not a bigger problem.


I will keep driving it this week and check if I can see dye light up the engine oil. I thought I saw it once, on the oil cap's gasket, but I tried it again yesterday and I couldn't see anything. I even took a drop of oil from the dipstick after it had been sitting and put it on a white card along with a fresh drop of oil to see if I could see any thing under black light--but nothing.

https://www.amazon.com/Interdynamics-375CS-Radiator-Coolant-Dye/dp/B002M4E0VC


I apologize for the long-winded response :)
 
Ok so... you should probably start by getting your car up to temp... that doesn't mean driving it hard, but you need the oil temp to get up to temp to boil off any water.

Why did you change injectors?

Do you get the misfire while idling or randomly or what?

I assume you're stock?
 
EivlEvo said:
Ok so... you should probably start by getting your car up to temp... that doesn't mean driving it hard, but you need the oil temp to get up to temp to boil off any water.

Why did you change injectors?

Do you get the misfire while idling or randomly or what?

I assume you're stock?
Click to expand...

Thanks for your response EivlEVo, I changed the injectors after taking it to my mechanic for some exhaust work, he said that it seemed like one of the injectors were leaky. He was right. After putting new stock injectors in, it started up faster. However, I get hesitation when driving for the first minute or two. It feels like when you let off the throttle quickly in a low gear. Also, on a cold start, if you touch the gas slightly, it almost stalls, never does though. I will check the throttle position sensor wiring, since the tps is new. It would be nice to find what it is, since it's been puzzling me for months!
 
You can use an anaerobic thread sealant if you want to be sure. A thread sealant like loctite 592 for example. Really though as mentioned light oil is fine.
 
Are the plugs new after the injector swap? Were the injectors NEW or Reman or what? One of the signs of a leaking injector is a fouled plug.

Regarding this dye. You added this to your coolant post HG change and you've now detected it in your oil? But your compression looks good? Was this done by the book or did you add oil to get the numbers?

Is your car stock?
 
Hi EivlEvo, great questions! The injectors were remanufactured/ cleaned and flow tested. I didn't change the plugs because they were fairly new. The dye was added post head gasket installation, and no oil was added to the cylinders when testing. The first crank there wasn't really a response, but then it went up to 80 or 90 psi and built up to 145. Below are two pictures of the oil under black light for clarification. The car is completely stock. No mods whatsoever.

Dave, thanks for the loctite 592 thread sealant comment. This is what I was trying to think of. You read my mind!





 
Did the machine shop test the head for leaks?

The plug may have been fouled from before, and this might be what's effectively causing the mis-fire. Also... this would be compounded by the car not getting up to temp ever to cook some of that crap off the plug.

Have you tested for exhaust gasses in the coolant?
 
Hi EivlEvo, thanks again for the good questions. I did have the head pressure tested, and they said it was fine. Prior to this, I did a coolant exhaust gas test, and it was fine--no change in the color of the chemical. I will clean the spark plugs up this weekend and put some on order to see if that changes.

It only misfires under load for the the first couple minutes. I haven't replaced the Maf or knock sensor, and am not sure if either sensor malfunctioning would be causing the misfire or ping. Thanks again everyone for advice on this baffling problem.
 
durk80 said:
Hi EivlEvo, thanks again for the good questions. I did have the head pressure tested, and they said it was fine. Prior to this, I did a coolant exhaust gas test, and it was fine--no change in the color of the chemical. I will clean the spark plugs up this weekend and put some on order to see if that changes.

It only misfires under load for the the first couple minutes. I haven't replaced the Maf or knock sensor, and am not sure if either sensor malfunctioning would be causing the misfire or ping. Thanks again everyone for advice on this baffling problem.
Click to expand...

Yeah lets not go to the parts cannon yet. And fwiw using the good ole copper plugs seems to work best on the B230.

Once you get the new plugs in there, see if that solves the misfire.

In terms of your coolant mixing. I'm not certain what to say about that. You've plainly confirmed that you're getting coolant into your oil. The thing I might suggest is... if you've had HG issues before, it's very difficult to properly flush the motor of it all on one pass. Hell... I still have bloody ATF in my coolant from my stupid tranny cooler failing and I've changed the coolant twice and chemically flushed it once. So I wonder if you're seeing residual rather than primary?

I might say... if you're able to address the misfire, and you're getting good compression as you say you are, I would certainly monitor the HG by checking the oil regularly, but I might say it's fine and move on?
 
Hi, neighbor. I think you're over-thinking some of this. If you meet me at The Varsity and buy me a chili dog and some onion rings, I'll tell you what I think.
 
Wren said:
Hi, neighbor. I think you're over-thinking some of this. If you meet me at The Varsity and buy me a chili dog and some onion rings, I'll tell you what I think.
Click to expand...

That would be great! I'll PM you my phone number:)
 
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