3.4 : oil in coolant

[ssdurango]

The engine has been consuming about 1/2 liter of coolant every 1000km. Now I know where it's been going. Yesterday it drank about a liter and it went right into the oil. I'm hoping it's just the intake manifold. But what I'm going to do first is presurize the cooling system, look into the cylinders with the spark plugs removed with a borascope, to look for a cracked head or leaking head gasket.

A: Does anyone have a better idea on how the diagnose this?

B: If it was the head/head gasket, wouldn't It be over presuzing the cooling system?

Thanks for the input

[geoffinbc]

Do you get white steam at startup? When my head was cracked on my Trooper it billowed white smoke for about 5 mins. When the engine was finally hot and all the residual coolant was burnt out of the cylinder you could not tell. Eventually it got so bad the starter could not crank the engine over because of the water in the cylinder.

[pocket-rocket]

Don't the iron heads have a problem with cracking heads? If it were overpressureizing your cooling system it would pop a hose or radiator. I've had cars where compression was leaking into the cooling system from a bad head gasket, and it never blew anything up, luckily. One sign it did give though, was no heat inside the car and it would puke coolant out of the radiator at you after it warmed up and the bad spot in the head gasket started leaking. Otherwise on a cold engine, it acted completely normal.

[ssdurango]

No, there is no white smoke, so that's a good sign. But there is a fram oil filter on it! (What's that all about anyways?)

[robertisaar]

No, there is no white smoke, so that's a good sign. But there is a fram oil filter on it! (What's that all about anyways?)

anti-drainback valve...

and the shitty filtering material

basically, everything that its supposed to do, it doesn't...

[ForcedFirebird]

I just had a customer with this same problem, and it was never solved. He bought a set of ported/modified heads, put them on with a 260h cam, and not soon after had oil in the coolant. He didn't like the idle quality of the 260 and bought a custom cam from me, put it all back together and the problem went away, reason for the coolant is unknown.

[robertisaar]

I just had a customer with this same problem, and it was never solved. He bought a set of ported/modified heads, put them on with a 260h cam, and not soon after had oil in the coolant. He didn't like the idle quality of the 260 and bought a custom cam from me, put it all back together and the problem went away, reason for the coolant is unknown.

maybe some of the bolts were torqued wrong during reassembly? and then the second time around, it was done right?

[ForcedFirebird]

maybe some of the bolts were torqued wrong during reassembly? and then the second time around, it was done right?

Perhaps. I didn't do the install

I have yet to have a warranty call **knocks on wood** but that was my biggest scare. I though maybe the heads were cracked after being beat up in the machine and/or from the porting lol.

I have a feeling it was a gasket failure due to improper installation (either tq specs or a RTV issue), but he didn't even show me pics of the old gaskets. I have been blessed with 20/13 and 20/10 vision (ask the guys at the meet how I nailed a skunk with a bottle from 30yds), but I still can't see 1500 miles away rofl.

[60dgrzbelow0]

Don't the iron heads have a problem with cracking heads? If it were overpressureizing your cooling system it would pop a hose or radiator. I've had cars where compression was leaking into the cooling system from a bad head gasket, and it never blew anything up, luckily. One sign it did give though, was no heat inside the car and it would puke coolant out of the radiator at you after it warmed up and the bad spot in the head gasket started leaking. Otherwise on a cold engine, it acted completely normal.

Yes... Prone to cracks... in part from the residue of sharp edges (post-machining) that invite failure from so many razor-edged stress points. Not treating these invites hot spot stress points from the thinned edges to crack. A few minutes with a rat-tailed file to dress them up goes a long way toward reducing such failures. (See attached photos...)

[60dgrzbelow0]

The engine has been consuming about 1/2 liter of coolant every 1000km. Now I know where it's been going. Yesterday it drank about a liter and it went right into the oil. I'm hoping it's just the intake manifold. But what I'm going to do first is presurize the cooling system, look into the cylinders with the spark plugs removed with a borascope, to look for a cracked head or leaking head gasket.

A: Does anyone have a better idea on how the diagnose this?

B: If it was the head/head gasket, wouldn't It be over pressuzing the cooling system?

Thanks for the input

This topic of coolant leaks has been popping up more an more. Without impugning any other source for the head gasket installation procedures... the attached images cover this treatment in some greater detail than the typical Haynes Manual that might prove useful. I keep wondering if either the quality of the head gaskets is diminishing or that they are being inverted or installed on heads that are simply not up to the standard of being within a flat and level state of at or under .003 inch deviation from being perfectly flat. As for the torque sequence and pattern, since there are only four bolts per cylinder, approaching "squeeze" perfection here seems critical in getting the heads to lay down and stay there. Here are some photos on the subject..

[robertisaar]

that book needs to be mass produced.... now

[60dgrzbelow0]

that book needs to be mass produced.... now

Agreed. When I first started working on a complete 3.4L Engine Tear Down and Re-Build ...I wanted to get a wide range of information which included the GM F-Body Carline Series Shop and Service Manuals (eBay $40.00) as well as any Haynes books available to get up to speed on the 60 * engines and while searching the net via Google... I stumbled across this book.

Unfortunately...it was being marketed on Amazon and few of the rare book online sites to the tune of an unbelievable price of $350.00. So...I shined that idea on and searched for it on eBay. I got lucky one day and picked up a used copy for a mere $14.00 plus S&H after staying up all night waiting for the bidding period to close. Nobody else saw it, so I snatched that bad boy up the instant I was able.

The book has proven to be well nigh indispensable. I am very surprised that with all the enthusiasm for our little V-6 Power Plants that it has not been re-printed for sale many times over. But... if there is anything specific I can provide for the group... just let me know what section of interest you have and I'll scan the pages and send them as a high quality JPEG via email.

The only weak point in the publication is that it has very little information on tuning and high performance tweaks. But for the basics in engine building ... this has proven itself time and again as the very "Bible" on the subjects that the V-8 manuals never cover.

[60dgrzbelow0]

About the other issue with finding engine oil in the water... Sadly...a crack in either an engine block gallery adjacent an impinging water jacket... or a cracked cylinder in a similar area are the other two nightmare scenarios that prevail as possible explanations of the problem. Can you see palpable drops of oil floating in view from the open radiator... or is the there just a slick on the surface? Do you also have muddy looking oil in the crank case as well? You mentioned a concern about the engine being exposed to freezing conditions in the months to come and the worry of not having Poly-Ethylene-Glycol in the mix with your coolant water. Did the engine block go through a prior cold season with only H2O inside?

[ssdurango]

Sorry, I have coolant in the oil, not oil in the coolant.

So I removed the the lower intake manifold, Inspected and cleaned everything. I replaced the gaskets, torqued the manifold back down, presure tested the coolant system and coolant is STILL dripping out the drain plug hole. I looked in the the cylinders with a borascope and they all looked dry. I'm stumped. help.

[ssdurango]

I found the leak - it was coming from the head gasket. The gasket material bewteen the fire ring and inside edge of the gasket is eroded away at #4 and #6 cylinders. #2 is on the way out too, all in the same place. These are new felpro gaskets, installed in april with ARP headstuds.

I looks to me like the compression presure has blown out the softer material leaving the steel mesh behind. I'll upload some picture soon...

Has anyone seen a 60v6 fail like this?

I'm running a 3.4 iron head, Supercharged - on propane. 300hp.