losing coolant after h/g replacement

[semlin]

ok, it's official. I'm losing coolant steadily since the truck went back on the road. I hesitated to report it until now because i thought I might just have post-traumatic-head gasket replacement syndrome, but, after I had to add 1 litre to the overflow on Sunday from a cumulative drop from wednesday, I am still seeing a further small drop in fluid in the overflow each day even after travelling short distances. I have smelt the very occasional whiff of burnt coolant on highway driving that might be other cars. I have triple checked the rad and every hose when hot and running, and I have inspected the head/block seam. I see nothing. the engine is running smoothly. oil does not look contaminated and no condensation in the oil cap.

my thoughts are, bad hose fitting only leaking under pressure or a cracked head into the valve area ala doug. I can't really see the new h/g itself failing but i suppose perhaps I did something wrong. the head was pressure tested by the machine shop so hopefully it is just a hose or maybe the rad.

so I'm thinking i need a pressure test or should i go with a dye test?

 

[tech_dog]

That's a bucking fummer.....

It's a hose. I'm sure it's a hose.

Good luck.

 

[cruiserdan]

Pressure test.

Sonofabitch Simon, that is NOT fair!

 

[landtank]

I went through that as well. Did you replace the cooling lines to the throttle body? Those leaked on mine as well as the goose neck on the upper front of the head and one end of the phh.

 

[e9999]

dye!

I feel for ya! good luck!

 

[IdahoDoug]

Yeah, do the dye/light/special glasses thing. Find the light that's on a flexy wand so you can put it down places - you'll be extremely glad you did and it's no more money.

When reassembling, you likely reused several hoses and that's typical of all of us - myself included. A new hose will properly bond to the metal part, but a used hose may not. You'll find that one of these hoses is likely leaking. If you're sure it's not going into the oil then it's going to be external. If you end up not finding that, I'll lead you through pressure testing with the valve cover off as I did myself. I don't think you'll get to this - it'll be a hose. Also, mine had crud in the oil cap immediately.

DougM

 

[CJF]

Simon,

My heart literally sank as I read the title of this thread.

Great advice has been given; good luck and of course keep us posted.

Curtis

 

[IdahoDoug]

So? And? Yeah???

Heh....

DougM

 

[semlin]

thanks folks. i tried without success to source a reasonable pressure or dye test set today. all is can find are kits over $150 so i'm going to have to find a shop to do it.

doug, did you notice any problems with delayed firing up when starting after standing for a prolonged period with your 93 when you had yours crack issues? this is the only other out of the ordinary symptom i have. it used to start right up every time.

 

[Riley]

I too am sorry Simon...talk about bad luck....

I'm afraid to check my block for HG leaks this weekend as I'm not sure what I'd do....

 

[IdahoDoug]

Simon

Nope. The crack was on the 97 but it simply watered down the oil. When the 93 had coolant going into the #6 cylinder it did have some faint starting delays and also idled rough. But I also had cylinder pressure bubbles in the overflow tank.

Yeah, the pressure tester is bucks. We have rentals in the area for it but guess not up there, eh? No AutoZones? The dye/light/glasses kit is around $20 so well worth it. The dye kit is really all you need for the time being as the engine pressurizes the system enough for your leak to happen so you just need to find it. After shutdown and cooldown you could pull the plugs and get atop the engine to see if you can see any glowing through the plug hole atop the pistons. I used a mirror for cyls 5/6 and the others were easier.

But first I'd be all over the EXTERNAL parts of the block. I'm well and truly convinced this is your issue. Look closely at the bottom of the upper radiator hose where it mates with the block, and also recheck your PHH. There's also the ones at the rear of the head into the firewall.

DougM

 

[e9999]

be sure to get a dye that you can still see after the coolant has evaporated / dried off...

 

[semlin]

would love to find the $20 dye kit doug mentions. nobody here seems to have one for under $150.

 

[cruiserman]

A liter is a lot of fluid over 1/2 week of driving. I doubt it's being burned.

 

[sdbrassfield]

How long has it been on the road since the repair? It will take a more than a little driving to get all the air out of the system and settle down. Have you run the system w/ the heat on for a while to get all the air out. Just thinking of the basics....not the bad things....

 

[semlin]

it has gone 150 miles with sustained highway and around town miles. heater has been on nearly the whole time on purpose.

 

[sdbrassfield]

Have you figured this one out yet ?

 

[semlin]

ok finally managed to get the pressure test done

there were some heater hoses leaking pretty good that are ok now. however, it would not hold 15 psi after they were addressed and stopped leaking. over maybe 25 minutes it dropped down to 13 psi. the mechanic was not sure if the problem was in the gauge as he had to use a plastic adaptor he did not trust. there was no evidence under or in the truck of any leakage.

other data points. my rad cap is bad and would not hold pressuyre so i'm replacing that tomorrow. that will presumably increase coolant leakage if I still have any.

also, as I suspected, I was low on coolant at -23 celsius on the refractometer which the guy thought was about 40% coolant/60% water. I will address this as well. when i refilled i did not compensate for the amount of water inside the block after a prolonged flush.

 

[cruiserdan]

I suspect you are OK.

 

[semlin]

thanks but i'm still holding my breath.

incidentily, why doesn't the air leak out of the overflow when you do this test?