Combustion leak detection

I saw a video posted by TST seminars using their Bull's-eye leak detection system to id a head gasket leak.
The test was just like when Paul uses a 5 gas analyser in the overflow bottle to detect hydrocarbons.
It got me thinking that there must be similar affordable tools that can detect hydrocarbons, and I found these on eBay. Here
I wonder if they'd be suitable for the same use.

We had one of those Bull's-eye kits to try last year. The leak detector seemed to work well in finding a head gasket failure. I ended up sending it back not for what it could do, but rather what the owner of the company did to TDC overlays (that's another topic)

However, if I recall, it detected CO or CO2 and not HC's. I am not completely sure but I think that's how it worked. It was also used for A/C and evap system leak testing using CO or CO2 charge canisters. So I would think a CO or CO2 and not a HC detector would be better at finding a failed head gasket. On the other hand, I know the block test fluid detects CO and CO2 and not HC's and does a poor job of it at times. At 20 bucks it might be worth getting both types and doing some experimentation.

Ro-longo wrote: We had one of those Bull's-eye kits to try last year. The leak detector seemed to work well in finding a head gasket failure. I ended up sending it back not for what it could do, but rather what the owner of the company did to TDC overlays (that's another topic)

Truth I'm still kinda salty about that one.

So who's gonna be the guinea pig and order one of these eBay gadgets for testing purposes?

Tyler wrote:

Ro-longo wrote: We had one of those Bull's-eye kits to try last year. The leak detector seemed to work well in finding a head gasket failure. I ended up sending it back not for what it could do, but rather what the owner of the company did to TDC overlays (that's another topic)

Truth I'm still kinda salty about that one.

So who's gonna be the guinea pig and order one of these eBay gadgets for testing purposes?

I must have missed something..
As far as guinea pig, that's the thing. I'd have to wait for a car with a bad head gasket to see if it works.

Noah wrote: I must have missed something..
As far as guinea pig, that's the thing. I'd have to wait for a car with a bad head gasket to see if it works.

Ah sorry sir The story goes that Automotive Test Solutions tried to (or successfully did?) patent all software having to do with timing overlays and in-cylinder compression waveforms. People like The Driveability Guys used to produce overlay software, but can't any more

Yeah, we do see popped head gaskets occasionally, and we usually use the five-gas to verify. I was thinking about buying one, and keeping it around to compare against the gas analyzer when the opportunity came...

The software overlay saga was just so wrong there is actually a way of creating your own but using it is a pain.
Cylinder head gasket failure can be one the hardest things to diagnose, you eliminate everything else then it all comes down to one of those gut feeling things. At the moment testing the gases in the coolant tank by whatever means available is the best test we have. Although I have heard of UV dye in the coolant showing up in the tail pipe gases.

I think there should be enough HC in the crankcase gases for a test?

Speaking of head gasket failure testing. This is what I got when I stuck a fuel tank pressure sensor in the radiator filler neck of a Honda Pilot with a blown head gasket.

Thats interesting. Would you mind going over the set up?
I'm guessing the engine was probably cold, system not pressurized? And what's your synch trace, and did that help ID the cylinder with the problem?
I'm currently salvaging FTPs out of GM tanks at the junkyard to make a rig like that, I never would have thought to try it on the radiator to check a head gasket..

Ro-longo wrote: Speaking of head gasket failure testing. This is what I got when I stuck a fuel tank pressure sensor in the radiator filler neck of a Honda Pilot with a blown head gasket.

Hey, that's cool! Like Noah asked, setup? Very interested to try this.

Just curious, how bad was this head gasket failure? Like, misfiring? Or, just overheating?

Tyler wrote:

Ro-longo wrote: Speaking of head gasket failure testing. This is what I got when I stuck a fuel tank pressure sensor in the radiator filler neck of a Honda Pilot with a blown head gasket.

Hey, that's cool! Like Noah asked, setup? Very interested to try this.

Just curious, how bad was this head gasket failure? Like, misfiring? Or, just overheating?

.

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That's a good question too.

Noah wrote: Thats interesting. Would you mind going over the set up?
I'm guessing the engine was probably cold, system not pressurized? And what's your synch trace, and did that help ID the cylinder with the problem?
I'm currently salvaging FTPs out of GM tanks at the junkyard to make a rig like that, I never would have thought to try it on the radiator to check a head gasket..

As far as the set up goes, Cold engine, and water pump belt off. The sync in #1 ignition coil trigger, I was trying to see if I could identify the which cylinder but it didn't work as I wanted.

And for the tool set up I used a standard fuel tank pressure sensor with a 1K ohm resistor on the B+ feed to drop it down to about 5v. Then I used an adapter out of my LANG Exhaust backpressure tester . If you follow that link, its the little rubber cones.

When I got the vehicle all the RO said was "2nd opinion on if it needs a motor". I had pulled it in my bay over the weekend and when I went to start it the next Monday it would not start, even though two days prior It started and ran fine. After doing all the basic checks for a crank no start, I took the radiator cap off and noticed pressure in the cooling system. That's when I decided to put a pressure transducer to see what results I could get.

When I did it with the water pump belt on I got a very different signal, then I took off the belt and got that signal. I have the trace on a/c coupling and inverted, the GM pressure transducer is aboutn1.5v atmospheric pressure and pressure makes the voltage go towards zero. I did a running test as well but forgot to save the file.

I have done this test on a couple of other vehicles and I can see a pressure increase but at a steady rate. The Honda was a very bad failure. And both other times the engines were cold, I don't think this will work on a warm or hot engine.

Even if the head gasket is perfect you will see a regular pressure pulse in the coolant tank.
This known good 4 cylinder at idle was taken with a FirstLook style sensor, with a hardware filter to take out the higher frequency noise. Pulses corespond to each compression stroke.

Andy.MacFadyen wrote: Even if the head gasket is perfect you will see a regular pressure pulse in the coolant tank.
This known good 4 cylinder at idle was taken with a FirstLook style sensor, with a hardware filter to take out the higher frequency noise. Pulses corespond to each compression stroke.

I was wondering if that would be case. You answered the question before I could ask it, thanks Andy!
Was that capture with the water pump belt off like Ro-Longo's capture?
Obviously that would be unrealistic if the pump were timing chain/belt driven.

The water pump was driven of the cam belt, the low pass filter took unwanted water pump noise out.
I am wondering if an engine is pumping gases into the coolant if the rate of rise of the pressure in the coolant could be a usuable test, problem is there is a huge number of variables involved between different vehicles and ambient conditions.

I like the 5 gas analyzer in the coolant tank test i have a snap on hhga5b 5 gas can anyone tell me if it will work on a diesel engine?

Tyler wrote:

Noah wrote: I must have missed something..
As far as guinea pig, that's the thing. I'd have to wait for a car with a bad head gasket to see if it works.

Ah sorry sir The story goes that Automotive Test Solutions tried to (or successfully did?) patent all software having to do with timing overlays and in-cylinder compression waveforms. People like The Driveability Guys used to produce overlay software, but can't any more

They do have a bunch of patents: patents.justia.com/inventor/bernie-c-thompson

I've had some success using a combustible gas detector for head gaskets. This is a 99 Cadillac that was a complaint of overheating and coolant loss. The ones that I have had the chance to use this on have been pretty obvious. It will not work with diesels.

That looks far superior to the cheap ones I was checking out.
I googled the part number visible on the face, and it seems reasonably priced as well. Thanks for sharing!

Hi folks! I'm not sure if this is in the right spot or not, but I have a question on 5 gas analyzers. I am looking for something more accurate for detecting blown head gaskets than what I currently use which is the regular combustion leak detector kit with the fluid that changes color. I'm considering buying a 5 gas analyzer. Snapon has their hand held unit on sale for $2,500.00 currently. Any thoughts on whether that is a good working and accurate unit? Other suggestions are welcome on brands to buy. I'm mainly interested in using this tool to test for blown head gaskets, but maybe there are other things it would be useful for? I'd be interested in hearing what else I can do with this tool. I'm in Mississippi, so emissions aren't much of an issue here....there are no vehicle inspections. Thanks!