Losing coolant, bubbles in overflow, slightly rough idle...head gasket? (1 Viewer)

[Death Star]

So... I just noticed my overflow tank empty after I filled it last week. I checked the radiator and it was low too. I refilled the radiator and overflow and checked for bubbles. Definitely have them. Big bubbles. Temperature gauge stays in the middle, always has. Idle is a little "lumpy". No steam from exhaust and it smells "clean", not sweet.
Oh, and a side note, my oil pressure gauge just quit...

 

[Whileemptyheadsdream]

Sounds Like could be. Sorry Do a Compression ck. Is coolant like a milkshake. ? If loosing coolant and no hoses or lines are leaking there Is a good chance she's blown. I have not lost a H/G so I'm not the most educated member on this Issue. I have read dozens of posts and If you have milkshake coolant head gasket problems are most likely the reason. Good Luck. !

 

[OffGridOverland]

Purge the system of all air. Then watch. Pull the cap off the valve cover and look for the milky brown oil under the cap.

Id be very careful if your oil gauge stopped. You might have the same issues mine had. Now I am putting a rebuilt motor in.

 

[Whileemptyheadsdream]

This may help you. !!

https://forum.ih8mud.com/threads/how-to-tell-if-your-head-gasket-is-blown.430839/

 

[sbman]

These are classic symptoms of a blown head gasket. The oil pressure sender just happened to break at the same time? I'd be very careful, easy to take it from replace head gasket to replace/overhaul entire motor.

 

[Death Star]

So far there is no oil contamination. I changed the oil last week and all looked ok. The oil pressure sending unit is very rusty and the wire is very loose. I'm thinking the signal wire rusted off

 

[sbman]

Oil contamination isn't necessary to diagnose a blown head gasket. The leak can be from combustion chamber directly to the coolant passage. High cylinder pressures push exhaust gases into the cooling system, which blows exhaust (and coolant) out the radiator cap and causes further overheating due to low coolant, causing warping of head. There really is no other source for lots of big bubbles. Continued use can cause boiling/evaporating coolant to pit the cast iron block requiring cylinder decking (remove entire engine). I'm currently doing a full rebuild on mine due to previous owner running it on a blown head gasket.

If it is running rough a compression check should tell you which cylinder it is. It's the low one relative to the others. The one with the clean spark plug.

 

[retrofive]

x2 comp test and leak down test kit from your LAPS.

 

[sbman]

Also, if you are really unlucky, coolant can fill the cylinder overnight and on morning startup.... broken rod, broken block, etc...

 

[Death Star]

Ok...now no bubbles in overflow... I'll pull the plugs after work tonight. The idle isn't very rough, just a little more than usual.

 

[nukegoat]

A coolant leak is possible. Then filling up the dry system will take some time to purge the air. If not an external leak it's possible that it's a head gasket

 

[Death Star]

I'm praying I find an external leak. So far no luck. Further investigation tomorrow.

 

[sbman]

It's tough for it to be an external leak and causing bubbles. There really isn't any place that can do that, the whole system is under 10+ psi of pressure. Fixed promptly without further damage a head gasket isn't terribly expensive. Fix the impossible to reach hoses while you are in there, and install a real temperature gauge for peace of mind. I don't believe these things 'just go', it's a by product of the conservative temp gauge that hides cooling system deficiencies. IMHO.

 

[LINUS]

Sounds like you really would benefit from a hydrocarbon test kit for the coolant.

At the auto part store it's the kit of fluid you hold in a vessel in place od your radiator cap while the motor is running.

The fluid is yellow & will turn blue / purple when exhaust passes through it via your blown headgasket.

The kit is ~$40 & you'll know right away.

 

[Death Star]

I check yesterday and no more bubbles. It must have been air purging from the radiator from topping it off. I will continue the investigation today. Wish me luck. I'm not looking forward to doing a head gasket.

 

[sbman]

Another thing to look for is pinholes in small coolant hoses or radiator. Those can be pretty hard to find and a source of slow mystery coolant loss. Shutting down hot and the listening carefully in a quiet place can be effective for that, you can usually hear a slight hissing sound from the cooling system pressure bleeding off.

 

[Death Star]

#6

 

[Death Star]

#1 cylinder

 

[Death Star]

#2

 

[sbman]

#6 looks like it has a pink/red tone on the insulator, but it's picture is different lighting than the others.