is this a sign of blown head gasket?

[laotsu]

checked the coolant on the truck this morning. Cold.

This is the truck that just did a 382 mile journey in eight hours.

 

found a little scum on the surface of the coolant (oil?)

 

this is what it looks like when I stuck my fingers in it

 

 

 

there's no "mayonnaise" in the oil

 

oil is dark and needs a change but at level.

 

valve cover interior shows normal oil spray.

[cj8281]

Check your oil and see if there is coolant in the oil. Sometimes on a long trip shit will get stirred up, oil will collect at the top of the radiator as it is lighter than the coolant. You might be at the beginning of a head gasket going bye bye.

It might just be that a little bit of oil has worked its way from the high pressure passage to the coolant as the coolant is at a lower pressure than the oil. However when you shut off the engine, coolant can now work it's way into the oil passage.

[laotsu]

Check your oil and see if there is coolant in the oil. Sometimes on a long trip shit will get stirred up, oil will collect at the top of the radiator as it is lighter than the coolant. You might be at the beginning of a head gasket going bye bye.

It might just be that a little bit of oil has worked its way from the high pressure passage to the coolant as the coolant is at a lower pressure than the oil. However when you shut off the engine, coolant can now work it's way into the oil passage.

thanks for the tip

 

I did check the oil. The "mayonnaise" I was referring to is a term I have heard used to describe a mixture of oil and water often found in blown headgasket engines.

[dr.feltersnatch]

get a block tester and test it. i think auto zone rents them for free

[bananahamuck]

If it had slight leak PO might have just filled it with dirty container ,, flush it out and see if i comes back.. 

 

 

happy thoughts .

[metalmonkey47]

Could be rust/crap in the radiator/block breaking up. 

Compression tester/leakdown tester is a rental at AZ. 

[datzenmike]

Maybe just scummy old antifreeze/coolant or something added to the rad water from a dirty container. Reverse flush it and the bock/heater.

[Draker]

I wouldn't worry about that... flush it and monitor.

[datzenmike]

I've never see the oil jet in the block leak into the water jacket or the other way round. It's well sealed, but if the head was wildly warped I could entertain the possibility. 

 

Water in the oil is most likely water drawn into the cylinder from a failing HG and compression of the heated steam pushes it past the rings to condense in the crank case. It could also be, but less likely, a crack or erosion of the back of the timing cover behind the water pump.

 

Oil in the water is likely compression leaking into the water jacket from a failing head gasket. If compression is leaking into the cooling system it will over pressurize and push coolant out into the over flow bottle or if old enough, just expel out onto the ground. Coolant may be dirty and smell of gas. Unexplained water loss and constant topping up every few days could be this.

 

I have blown a HG out the plug side of the block around #3 before and also a warp between #2 and #3..

 

 

A compression test will barely confirm a totally blown gasket and isn't that reliable for one in the process of blowing. Two adjacent lowish reading cylinders or one low with water on the plug tip... probably is. Coupled with steamy exhaust, overheating and coolant loss it almost for sure.

[arizonajones]

Sorry to thread jack, but I just started having a similar problem, so why make a new thread?....

 

Anyway, is it safe to assume 'bad headgasket' if coolant is blowing out of the reserve tank and the (pretty fresh) coolant smells of gas?

-I haven't had any smoke or steam (but my temp gauge stopped working so I don't know how hot it's running, either.)

 

Is there a direction to start in before assuming its the HG? I've just replaced the rad cap (cheap & easy stuff first, right?) and I'm wondering if it's worth it to pull apart the water pump and look at the timing cover, or if the gas-smelling coolant is a tell-tale sign of an HG issue.

 

Thanks for letting me sneak into this thread!

[datzenmike]

Very possible that the gasket has failed between the combustion chamber and a water passage. At the most the cooling system can run up to 13 PSI, usually much less. Compression before ignition is over 150 PSI and who knows, maybe 10X that after. Is it any wonder that some might get in the system and pressurize it? Excessive pressure above what the rad cap is rated at will vent into the coolant recovery bottle.

 

 

Warm up with the cap off and reasonably full of coolant. Watch for bubbles. This would be compression forcing it's way into the coolant. It might even overflow the rad. Gas smell is also a good indication.

[laotsu]

I never figured mine out, just built and installed a motor.

[wayno]

Are you saying you have oil in the radiator water, or the radiator water is being blown out the top of the radiator when the cap is off?

When you pull the valve cover off, check the headbolt closet to the thermostat housing, is it loose, or do you have water coming out from between the block and head anywhere?

Sorry to thread jack, but I just started having a similar problem, so why make a new thread?....

 

Anyway, is it safe to assume 'bad headgasket' if coolant is blowing out of the reserve tank and the (pretty fresh) coolant smells of gas?

-I haven't had any smoke or steam (but my temp gauge stopped working so I don't know how hot it's running, either.)

 

Is there a direction to start in before assuming its the HG? I've just replaced the rad cap (cheap & easy stuff first, right?) and I'm wondering if it's worth it to pull apart the water pump and look at the timing cover, or if the gas-smelling coolant is a tell-tale sign of an HG issue.

 

Thanks for letting me sneak into this thread!

[arizonajones]

Are you saying you have oil in the radiator water, or the radiator water is being blown out the top of the radiator when the cap is off?

When you pull the valve cover off, check the headbolt closet to the thermostat housing, is it loose, or do you have water coming out from between the block and head anywhere?

The coolant is blowing out of the cap and the reserve tank as I drive. I don't see actual oil drops in the water, but it is brownish and smells like gas.

I'll take the valve cover off tomorrow and check the bolts. I don't think I water coming out of the block anywhere. Also, I just changed the oil and I didn't have any frothiness in the oil.

 

Very possible that the gasket has failed between the combustion chamber and a water passage. At the most the cooling system can run up to 13 PSI, usually much less. Compression before ignition is over 150 PSI and who knows, maybe 10X that after. Is it any wonder that some might get in the system and pressurize it? Excessive pressure above what the rad cap is rated at will vent into the coolant recovery bottle.

 

 

Warm up with the cap off and reasonably full of coolant. Watch for bubbles. This would be compression forcing it's way into the coolant. It might even overflow the rad. Gas smell is also a good indication.

I'll check for bubbles tomorrow. Also, (possibly a dumb question) if the compression is forcing coolant out the top, does that mean its keeping coolant from entering the block? 

[datzenmike]

No, water always seeks the lowest level and will flow through the the lower rad hose into the block, but the level will get lower and lower over time.

[wayno]

Sounds like you blew a head gasket, it doesn't mean that water will go into the oil, it sounds like one of the cylinders is pumping air into the water jacket, I had this happen on my brand new LZ23 block, the threads pulled out on the head bolt closest to the distributor, so I had to pull it apart and take it to the machine shop to have it fixed right.

I used a head stud kit when I put it back together, never had an issue since.

This is the one I bought.

http://www.ebay.com/itm/ARP-HEAD-STUD-KIT-NISSAN-DATSUN-L20-Series-202-4201-/360619223064?pt=Motors_Car_Truck_Parts_Accessories&hash=item53f694a818&vxp=mtr

[Ant-dat]

I have seen the front cover gasket cause oil to get into the water way,

[arizonajones]

Hi guys. I did some hunting today and took some pictures:

 

-So I ran it for a while with no cap and watched the rad fill up, but no bubbles I could see.

-made sure all head bolts were torqued to 60 ft/lbs (in the correct order)

-Tightened all the bolts connecting the front cover

-took it for a drive - drove ok, maybe a little less power, and burned more gas than usual.

 

This the front passenger side. I could see moisture at the front cover and onto the front corner of the block.

 

This is the back end (passenger side) more moisture from the block (but also looks like a new leak from that hose just started.)

 

View of the underside of the valve cover. No frothy splatter.

 

Kind of hard to tell, but this is the spray after driving. The reserve tank ends up full past the max line and the rad looks almost empty (after a drive)

 

 

 

So, that's the update. Looks like a strong possibility the front cover gasket is bad and the head gasket is on its way out too. Do you guys think it would be stupid to drive it around for one more day?

[banzai510(hainz)]

just monitor it.

This isnt a big deal yet buy get the knowlege and parts needed it does go out

MY gaskwets leak oil on my 510 and yester day I notice antifreeze from my 521, But will wait till summer to do a change if it makes it till then.

 

just watch the water usuage and ck for water in oil.

 

 

 

I dont show this as a show stopper. Just waych the TEMP also

 

 

tighten the clamp on the elbow on the head

[arizonajones]

just monitor it.

This isnt a big deal yet buy get the knowlege and parts needed it does go out

MY gaskwets leak oil on my 510 and yester day I notice antifreeze from my 521, But will wait till summer to do a change if it makes it till then.

 

just watch the water usuage and ck for water in oil.

 

I dont show this as a show stopper. Just waych the TEMP also

cool. will do. Thanks for the input.

[datzenmike]

There is only the oil jet area on the block and it's mate on the underside of the head where oil travels from the block into the head and it is well sealed and not ever a problem. If the gasket failed here oil would get into the coolant not the other way round. At the rear of the head is an oil drain back hole but this is not at pressure so coolant could get into the oil here. You have no indication of either so forget these two.

 

 

Hi guys. I did some hunting today and took some pictures:

 

-So I ran it for a while with no cap and watched the rad fill up, but no bubbles I could see.

-made sure all head bolts were torqued to 60 ft/lbs (in the correct order)

-Tightened all the bolts connecting the front cover

-took it for a drive - drove ok, maybe a little less power, and burned more gas than usual.

 

This the front passenger side. I could see moisture at the front cover and onto the front corner of the block.

 

This is the back end (passenger side) more moisture from the block (but also looks like a new leak from that hose just started.)

 

View of the underside of the valve cover. No frothy splatter.

 

Kind of hard to tell, but this is the spray after driving. The reserve tank ends up full past the max line and the rad looks almost empty (after a drive)

 

 

 

So, that's the update. Looks like a strong possibility the front cover gasket is bad and the head gasket is on its way out too. Do you guys think it would be stupid to drive it around for one more day?

 

Well this is to be expected if the gasket is blown internally... no visible external evidence. Other than the coolant recovery over filling. The rad coolant shouldn't be being expelled as this lowers the coolant level everywhere else inside the top the engine. Your call if you want to run it dry like this for any extended time.

 

Just wondering if the coolant siphons back into the cooling system when it cools. It should, if working properly. Do you have the proper rad cap on it? It will have two rubber seals not one. If working, at lease that which is pushed out is returned before the start of a new day.

 

I would get a gasket ASAP and at least be prepared to change it at any time. What happens if it suddenly get worse while away from home any distance?? My 620 blew, for no reason, years ago. Was spitting water out the plug side of #3. Gasket was $23 and that was the total cost to change it.

[arizonajones]

There is only the oil jet area on the block and it's mate on the underside of the head where oil travels from the block into the head and it is well sealed and not ever a problem. If the gasket failed here oil would get into the coolant not the other way round. At the rear of the head is an oil drain back hole but this is not at pressure so coolant could get into the oil here. You have no indication of either so forget these two.

 

 

 

Well this is to be expected if the gasket is blown internally... no visible external evidence. Other than the coolant recovery over filling. The rad coolant shouldn't be being expelled as this lowers the coolant level everywhere else inside the top the engine. Your call if you want to run it dry like this for any extended time.

 

Just wondering if the coolant siphons back into the cooling system when it cools. It should, if working properly. Do you have the proper rad cap on it? It will have two rubber seals not one. If working, at lease that which is pushed out is returned before the start of a new day.

 

I would get a gasket ASAP and at least be prepared to change it at any time. What happens if it suddenly get worse while away from home any distance?? My 620 blew, for no reason, years ago. Was spitting water out the plug side of #3. Gasket was $23 and that was the total cost to change it.

So I do have a new rad cap that is proper. The coolant does siphon back in after its parked a bit. I think today is it's last trip on the road until I can fix it.

[banzai510(hainz)]

This the front passenger side. I could see moisture at the front cover and onto the front corner of the block. no big deal I head worse. pressure wash every 3 months

 

this is not that of a big deal.

 

alway monitor the oil level and spots on the ground. and under the water pump for water loss

 

if its not overheating and using alot of water you can drive it locally in my opinion. If I went with the photos you have(unless your not telling me something critical) I would never drive my 510s/521 at all going by what you say,as they all leak. Mine all leak oil or a tiny amount of water with 30k miles.

510 30k miles oil leak at head gasket rebuilt motor

521 head gasket swap with Felpro gasket. I seen antifreeze yesterday. Im still driving both.