mystery coolant consumption

[bigbillyboy]

This forum has already been a huge help to me.  First off, the engine in question is the D24t; which is the 6cylinder version of the 1.6TD that is found in 1980's volvos.  I just completed a rebuild on the 1985 760 GLE in my signature, and it is now using coolant.  I've got about 500 miles of mixed driving on the rebuild.  When I had it apart, I had the head checked for square and pressure tested.  The head shop said it was all good.  I've done several head gasket repairs in the past, so I am confident that I followed all of the head torquing procedure to the letter.  It did this immediately following the rebuild, so I assumed that I had not torqued it correctly.  I pulled the head, had it checked for square AND pressure tested (again).  Head shop said all fine.

I read on here that the oil/coolant heat exchanger on these can be suspect, but generally results in oil in the coolant.  I do not have any oil the coolant, but do get the wispy white steam coming from the dipstick tube when up to temp.

Other than that, the thing runs fabulously.  I guess I'm just wondering if anyone else has had any experience with the oil cooler going bad, or if it is likely that the head shop missed something, and I'll need to pull the head (again). 

Also, I bought it 4 years ago with a tank of home brew bio diesel in it.  I ran about a half tank through it, then topped it off with regular diesel, not sure if old bio diesel can cause smoke or steam in the crankcase...

your suggestions are greatly appreciated.

Jason.

[macka]

How about coolant in the oil?

[bigbillyboy]

Nope.  Oil looks good. 

[RabbitJockey]

steam isn't abnormal when u open the fill cap or pull the dip stick out while its good and hot.  have u gained oil at all?  as in theres water sitting under the oil.  does your coilant have excess pressure in it?

[Runt]

How much coolant are you loosing?
Then the two simple suggestions:
First, I assume that you have run it in and topped it up a couple of times to allow the system to purge air bubbles and fully fill.  These engines are notoriously difficult to properly fill and purge.  It does help greatly to add a small bleed hole through the thermostat, and mak sure that it is installed on the higher side.  I also assume that you are maintaining the correct level in the reservior, and it's dropping to a low level.  If you fill the reservior completely it will always push some out and drop to a happy level.  I'm not trying to be nasty, but unless you've spent a little while working in a shop, you'd be surprised how often you see these sorts of things.
Second, have you done a pressure test?  You may be surprised to find that it's not going to the head at all.  Put it under pressure, let it sit, pump some more if needed, sooner or later you'll see a puddle form.  If you think it's HG, then you need to make sure that you check for the oil level rising, and I'd reccomend pulling either the glowplugs or injectors to check for leakage, and allow you to clear it when you are done.  At the very least, make sure you spin it several full revolutions by hand before engaging the starter, and then I'd pull the stop solenoid wire and crank for a while before I actually started it.  Hydraulicing an engine full of water can make an awful mess.
Good luck.

[truckinwagen]

I recently had a problem with losing coolant, it turned out to be a small leak in the lower rad hose(figured it out when it actually blew out on the highway an hour from home)


how old are the coolant hoses? many of them are probably the ones the car came with from the factory.
have any of them gotten diesel on them(almost all of the lower hoses have had diesel dribble on them)

I always suspect the coolant hoses first.

[bigbillyboy]

@ Runt - The oil looks good and black, and the level hasn't increased at all.  I've been watching it.  I've driven about 500 miles and had to add about 1/2 gal.  I add it to the overflow tank.  When warm, I fill to the "MAX" mark.  I have been carefully inspecting all the hoses, which looked really good when I put the engine back in, but I suppose it is possible to have a very small leak and not notice it.  It is mostly that it seems like an abnormal amount of steam.  I'll try to  post a video.

Just wondering how often the oil coolers fail, and if that might be a symptom.

[Runt]

I'm not sure I'm following you, if you're suspecting the oil cooler, but not seeing water in the oil or oil in the water?  Seems that if the oil cooler failed internally, you'd definitely notice crosscontamination.  Also, I'd assume that that contamination would very quickly mean a re-bearing, as coolant often causes major bearing problems.
If you're positive that it's leaking, and not externally, I'd  guess that your two remaining options are a cracked block, or a bad deck face on the block.  Did you check the block for flat when you reassembled?  It's a little harder with a diesel, but if you're getting leakage into the cylinders, you will probably notice a sweet smell in the exhaust, and often puffs of white smoke, especially on decel when the intake pressures are lower.
If you already know all of these things, then I apologize for not being much help, but I have no way of knowing what you may or may not know already.
Again, good luck.  I wasn't aware that the Volvo D. was so closely related to ours.

[vanbcguy]

Another thing to check... not sure if your engine has the plastic flanges on the head, but when they get old and brittle sometimes they start leaking a bit, but only sometimes.  For instance on Jezebel one would leak if I put a little sideways pressure on the hose (and then it would just pour out) but as soon as I let go it would appear to be fine.  Under driving conditions she'd loose coolant but sitting there idling or whatever there'd be no sign of a leak.

Other thing I'm wondering about - are you sure you got all the air out of the system?  If you're still purging air bubbles then it will appear like you're loosing coolant.

How much coolant loss are we talking about?

[bigbillyboy]

Sorry for the delay.  Family and work somehow always take precedence....

So, I shot a video of my engine running at temp, and it's the steam/smoke that concern me.  This engine has about 1000 miles on a complete rebuild.  The block was bored and the deck checked for flatness.  The head was checked prior to re-install.  About 500 miles after the rebuild, I noticed that it was steaming like this, so I pulled the head again, thinking I may have screwed up.  The gasket, and cylinders look good.  Just to be sure, I took the head back in and had it checked for flatness and pressure tested.  It was within spec for flatness, and had no leaks when pressure tested.

So, in my novice opinion, I have a cracked head, block, or something else, but am not familiar with the VW IDI engines and want some of your professional opinions as to whether I have a problem.  The car doesn't smoke at all (out the tailpipe) and runs fantastic.  I haven't noticed any leaks anywhere.  Thanks for your opinions.

Volvo running.avi

[theman53]

GUESS
I would guess break in proceedure. You have only driven a 500 miles in a month. That isn't the concern, but if it was driven at a steady RPM the rings won't be seating. Also, if you are using a synthetic oil dump it immediately and switch it over to a conventional oil. To me and I am a novice as well it looks like the rings just need to settle in. That video isn't coolant.

[bigbillyboy]

Thanks.  I'm using dino oil, and just getting ready to change it for the 3rd time.  I've tried to run it both hard and easy, so I'll keep breaking it it.  I'll keep you posted.

Jason