combustion leak tester question for the techs

[mrshaun]

When using this tool the blue fluid will change from blue to yellow on a gas motor and blue to green on a diesel motor. If it changes from blue to green on a gas motor what does that tell you? I would assume it would me exhaust is present in the cooling system, but I am not exactly 100% sure. anyone have any experience on this?
shaun

 

[mrshaun]

we put it by the exhaust pipe and it turned bright yellow instantly. but does anyone know why it would change colors when no exhaust is present in the cooling system?

 

[Mr.Nutcase]

THE combustion leak tester checks for combustion gasses leaking in to the cooling system(head gasket might be bad)

 

[mrshaun]

yeah we figured that, but it changes to yellow when exhaust gases are present. this one is changing to green. the other techs in town have had one or two that have changed to green on them as well. I have asked everyone so far this morning.

 

[MAD]

I would guess that there is either a very small combustion leak or the test fluid is old. Just a guess though.

You could try calling block check and ask their tech support.
http://blockchek.com/contact.htm

 

[turrican]

You might have accidentally sucked in some coolant - even a little bit contaminating the fluid can screw it up.

Edit/add: now that I think about it, I've seen this happen more than a few times. Possibly old fluid (isn't everyone's fluid old?) but I think it's more just something gets up in there, be it trace amounts of coolant or whatnot.

 

[Seanbev24]

Accidentally sucking in some coolant would be my guess, also. The coolant level needs to be low enough where the coolant can't be sucked up into the tester.

 

[mrshaun]

the level is real low. and there is a piece of plastic that prevents you from putting it down too far. this is not directly on a radiator. no contact with the fluid.
thanks for the tips/advise guys

 

[cheap bastard]

Why the two colors by design? They are testing for compounds. Could a bad head gasket combined with oil consumption show a green? The cylinder with the leak to coolant could also be the one using oil. When the tail pipe is tested, the rest of the engines volume exceeds the range of accuracy making the tester read the correct color.
No real knowledge here, just a speculation.
This could be tested by pulling plug or injector wires to see if the phenomenon changes. One could even remove plugs to see if one or more show oil combustion.

 

[scbird94]

Never had an explanation for this one. Had, however had it happen. In all cases where it has turned a shade of green, the headgaskets had NOT been bad. Cooling fan, wpump, etc have fixed it and car has proven by operation that the heads are ok.

Combustion leak testers are a tempermental, finnicky, black magic kind of tool. Sometimes you can test for an hour, and it will be fine. Short test drive, and it will fail in 5 seconds. The biggest key is to have it quite hot, to the point of overheating, and all of a sudden it will go mt. st. helens on you- and then you know.

Then there are the ones ive seen that have passed that test- and had bad head gaskets/cracked heads.

 

[mrshaun]

man there is no telling. the exhaust properties could have changed with the introduction of 10% ethanol. you never really know until someone smarter than you tells you so. or so I think..... oh well

 

[scbird94]

Anybody here use Ethylene Glycol test kits for engine oil?

Little meth lab lookin kit with glass tubes and vials, to test for coolant presence in engine oil. Very handy when you have a phantom coolant loss, or if you want to test the integrity/severity of an intake gasket leak.

Not many people use this method, because nobody has heard of it. GLY-TEK is the kits we get, they are made in st. paul, mn according to the box.

http://www.aviceda.com/nelco/kit.htm

 

[turrican]

In all cases where it has turned a shade of green, the headgaskets had NOT been bad. Cooling fan, wpump, etc have fixed it and car has proven by operation that the heads are ok.

Then there are the ones ive seen that have passed that test- and had bad head gaskets/cracked heads.

I never really trust those leak testers. In my experience, those times where there WAS enough exhaust gas coming through the coolant to turn the chemical yellow, you already knew the car had that problem because it would either be burping out of the neck, or you could see evidence of coolant in the cylinders ("steam cleaned" piston tops, etc.)

 

[Seanbev24]

Scbird- how much do those kits cost? I didn't see a price in the link. How many tests do you get per kit? I've never seen those, looks like a good option if the price is right.

 

[mrholeshot]

I've seen just the steam off of old Dex Cool turn it green. Not 100% testing with that stuff.

 

[scbird94]

Scbird- how much do those kits cost? I didn't see a price in the link. How many tests do you get per kit? I've never seen those, looks like a good option if the price is right.

We buy them in conjunction with another dealership, in bulk, and i honestly couldnt tell you what we pay.

We charge around $15/parts $15/labor for the procedure.

Email for quote is what they say, i have dealt with the folks at the company once, and found them to be very freindly. Whatever the cost, they are priceless in certain situations.

We sell use them almost daily as a recomended repair for people with 3.1/3.4/3.8 to guage the severity of their intake gasket leaks, to give them a timeframe as to how far they can drive it. Also handy in post-mortems, to determine the cause of a lower engine failure.

We had one a few months ago where a motor blew up, and a tech we had fired for sloppy work had done the intake a few months prior. The oil failed the coolant test almost immediately, and further inspection revealed loose bolts on the lower intake. We installed a low-miler used engine for the customer, and they were never happier.



I know they are available through our LOCAL napa, but it is a special order item, and i beleive they are the only store in our area to carry them.

 

[sberry]

I just bought one from NAPA, like 43$ P/N 700-1006, they didn't stock it but had it next day. It was tool/kit. Haven't opened or used it yet.

 

[scbird94]

Napa 700-1006 is the combustion leak tester. By far the best out of all the ones ive used.

I will look to see if i can get a part number for the glytek test kit

 

[Toolhorder]

Napa 700-1006 is the combustion leak tester. By far the best out of all the ones ive used.

I will look to see if i can get a part number for the glytek test kit

That glytek kit would be perfect for testing for coolant in oil when liners let go on Freelander engines. Currently I'm dropping the oil into a thin 3" coolant container bottom and looking for Dexcool orange droplets in the oil.

 

[Toolhorder]

I've seen just the steam off of old Dex Cool turn it green. Not 100% testing with that stuff.

Same here.

When I worked on Japanese cars especially Supras those testers don't work at all. The head gaskets fail on Supras all the time and you get return come backs all the time for coolant loss and you can't see where it's gone to even with the block tester.

 

[Stick]

man there is no telling. the exhaust properties could have changed with the introduction of 10% ethanol. you never really know until someone smarter than you tells you so. or so I think..... oh well

Changing fuels won't have an effect on exhaust gases in the coolant, as CO2 is still a result of the combustion process, along with CO, O2, unburned hydrocarbons (HC), and nitrous oxides (NOx). Block check kits aren't full of black magic voodoo. The fluid is Bromothymol blue, which reacts to CO2 (and the resulting PH change).

The reason that a gas engine turns the fluid yellow, while a diesel engine turns it green is because diesel engines produce less CO2 during the combustion process.

I've never had a false positive with a two chamber tester, and fresh fluid. If you have any doubt, let the fluid sit for a while in the tester, if it turns back to blue, there isn't a significant amount of CO2 in the coolant. Old fluid can also give false positives, as can single chamber testers if they **** up some antifreeze. Two chamber testers are the way to go.

Edit: One thing to realize is that a bad headgasket doesn't have to be "blown". These tests aren't supposed to be an all inclusive "bad headgasket/cracked head checker", only an indication that something may be wrong, and warrants checking into further.

 

[jrsavoie]

Is there a good combustion gas leak detector for a diesel engine.?

I picked a cheapy up from autozone. When I read the instructions, it said not for diesel engines.

 

[richfinn]

As Stick said, all the block tester does is react to the presence of Carbon Monoxide (the dangerous stuff that kills you) in your cooling system, it can be any component that allows exhaust into the coolant

In Europe we see a lot of EGR systems with liquid cooling as an example of how it can enter the coolant

Fresh test fluid and avoid cross contamination with coolant or you may mess up the test

 

[Iron-Iceberg]

I’m no expert but, I have tested it my self by breathing into the Napa kit. Just the CO2 in my breath changed it. So I gussed it would work ok.

 

[jrsavoie]

I was just going to return it, since it says, Not for use with diesel engines.

Does anybody know of a kit for diesel engines?
Thanks