I've shown this before with some mistakes and this one is no different. Probably why I've been sitting on it for a few years. But it's still a good on to learn from and also learn what not to do! Looking for a chemical kit? Check out my Amazon Affiliate page www.amazon.com/shop/scannerdanner
These chemical test kits can work if there's a large leak, but I can confirm that they aren't reliable on tiny leaks. I went through that years ago back in 2015 with a Civic that had enough of a head gasket leak to push coolant out of the overflow and maintain enough pressure on the system continuously that the coolant never returned to the radiator when the engine cooled off, but it didn't have any of the "normal" head gasket leak symptoms. Engine ran great, 210 PSI compression across all 4 cylinders, no bubbles in the radiator when doing a leak down test, no smoke from the exhaust, no coolant and oil mixing, etc. But sure enough, a new head gasket fixed it (common problem on the 1.7) and it's still doing great 8 years later. So while this is a cheap and easy test to try and a false positive is unlikely, don't rule out the possibility of a false negative.
I have used that tool a many of times and it shows no sign of head gasket failure even though coolant was going somewhere and it could not be found externally, I could take the spark plugs out and pressure test the system over a period of time and use a borescope and find coolant leaking into the cylinder. I purchased a gas analyzer just because of this. I work on flat rate so time is money and the risk of removing parts is avoided as well. The only time i have had it work is when all the signs of a failed HG are already there.
I am used to the old style tester too. You need air/gases from the radiator. If the coolant level is too high, take a couple of inches out of the radiator...there are a few ways to do that. Make sure the coolant is flowing so you get coolant that is coming the head. If it is a small leak, it is more likely to show in the results. Glad it's fixed...
We had a head gasket last year. The leak was so minor that it would run rough on startups and smooth out. We never block tested but I'm not sure that it would work, pressure test held 21 psi for well over 10 minutes but sure enough it was leaking coolant and had a slimy plug. Needless to say, we replaced the engine. Thanks for the video though! It's refreshing to see you mess up, lets us know you are legitimate as well as any potential issues we might have using the same test methods!
I have this same Lisle block test kit. For vacuum I usually just use my Mityvac vacuum pump. Hooks up quick and does the job. Thanks for the tips and teaching Paul!👍👍
I always pressure test the radiator cap . Since the radiator was changed , the tubes are probably not clogged . And I reverse flush the system , including the heater core . Many times a heater core is clogged . The radiator tubes usually clog in the center and are cold when blocked . Lucky it was only a defective thermostat .
Dan the man.. I just thought I'd pay you a compliment. Another excellent job of just sharpening one another. And you do an excellent job at it. Wow times have really changed from back in the days of encyclopedias.. back in the 80s when I was doing my best to mechanic my 67 Camaro. The knowledge that you share would have been so valuable then..
Love the weather, honestly I'm in that part of the world where the heat is around for the most part of the year, so snowing is a blessing😍 Thanks for sharing SD, Love this one😍 Special Thanks to cameraman Caleb😎 Stay Blessed Guy's🙏🏻
👍 you're the man as always! I used a kit from Amazon that didn't use any type of suction, only rising coolant pressure and it worked too. Thanks for sharing!
I used the best block tester kit available, the one with the two chambers and squeeze ball, gave it ten rev cycles while squeezing, and the fluid was still blue, but with a slightly greener tint than the unused fluid. I don't know what to make of it. What's the best place to get a decent five gas analyzer for cheap? Since I'm not interested in all five gasses, and I'm only interested in detecting hydrocarbons, is there a one gas detector that will work? Like one of those cheap flammable gas detectors on Amazon?
your strong vacuum source creates such large pressure differential, it lift the coolant into tester, use hand vacuum pump and sucks longer time. Blue liquid is a litmus solution test, CO2 changes to carbonic acid and the ph of solution changes to yellow, acidic color.
I don't use a bulb or intake source just for the reasons you had with sucking the coolant in. I use a Mighty Vac so I can control the intake of vaccum. I imagine it was a non OE thermostat used. I see that alot on Hondas by DIYers
Never saw that kit with a vacuum hose, only used the one with the squeeze bulb. Best one I ever had, I set the kit on the coolant bottle(hot bottle) and it turned yellow before I started the engine
Enjoy learning from your videos. When the vacuum caused it to burp it made me think that there is air trapped in the system causing it to overheat. Not an expert but I don't think vacuum would have drawn liquid out but it would draw air out causing the burp? Thanks for sharing your knowledge.
I went thru 3 Beck & Arnley tstats from Amazon for my Hyundai and they all lasted 1 day. They all Left me stranded after every repair. This was just a few months ago. Pot boil tested all 3 were stuck. Went thru rockauto and used Aisin all is good. You don’t get what is advertised anymore I guess.
I’m back to comment again but I love to just watch these videos just because. Also any oil mix would indicate a leak and if I suspect it I would send some oil to black stone to check for coolant anyway. Oil pressure is higher than coolant pressure so the oil will find its was to a lower pressure and mix. Also I would have turned the AC on to force the cooling fan to kick on.
Brilliant video Paul, your videos are fascinating, I wish I could have seen your videos when I was younger, I know for sure i would have perused a career in automotive diagnostics. Much admiration ❤
Paul - the possibility of the thermostat installed backwards ? Was one of my immediate thoughts as you were demonstrating the Co2 testing analysis - especially when the cooling fan was working ✌️
In the UK, the gas-analyser emissions test is the central part of the annual mandatory vehicle roadworthiness check, for obvious reasons: it helps remove polluting vehicles from our roads. Vehicle emission control was the driving force behind the introduction of OBD decades ago and has become increasingly stringent over time as we have become aware of the dangers of excessive emissions. So how come Pennsylvania dispensed with such an (apparently) important independent test? Have other states done likewise? I don’t suppose California has. Is it the belief that OBD on modern vehicles is good enough to detect emissions problems? But that would let older and badly maintained vehicles slip through the net. Seems such a strange decision. (I imagine the owners of the UK vehicle test stations would love to be able to be rid of their exhaust gas analysers for the fortune they would save in capital expenditure as well as the annual maintenance and calibration costs.)
Is the thermostat backwards. LOL. I ve done that early in my career. Head check should be first test on any overheat vehicle. At Mazda I check freeze frame at least. As long as 250 and lower I proceed to repair. 300 gets dicey and I do a block test.
I'm wondering if the cooling system is air locked and that's causing the overheating. One of our newer John Deere tractors requires the use of a Snap On coolant transfer tool that pulls vacuum on the system to refill and eliminate air pockets -
Hey Paul, why on the neck of the radiator's cap was bubbling if there is not a head gasket issue??? I thought bubbles came from a combustion leak...... NIce video as always!
I didn't see bubbles, but you can get bubbles from a few things. 1. A newly filled system that not all of the air is out of and 2. When the engine is hot and above the boiling point of water
I wonder if you remove the small hose that goes from the radiator cap port to the overflow bottle to allow some vacuum to escape and not allow the coolant to be sucked into the tool. Just a thought. Thanks so much Paul and Caleb for all your great videos.
That's what the small hole in the fitting was supposed to do, but I guess the vacuum source was too weak to use it? I don't remember. This was filmed like 3 years ago lol
On some makes and models you have no rad cap so has to be done through the overflow on those models sure you know that though! Just something that wasn't mentioned!
Why was the water pump replaced? Was the shaft mechanical seal leaking? Mechanics love to change water pumps when a car overheats but really these should only be changed if they are leaking or the pump is obviously damaged or as per a scheduled maintenance event (timing belt replacement). What do you think.
Awesome video as always . How about showing a bad head gasket using a pressure pulse transducer on your scope with a sync. I know its not always accurate but its pretty neat to show another use case of the lab scope.
I've had poor test results from that. No reason to complicate it imo. The only time I'd ever care to do that is if I wanted to know the exact cylinder that was leaking for a good visual inspection of that area once the head comes off. Other than that? No thanks! Too many variables!
@@ScannerDanner I agree. The scope is a great tool and pressure and pulse sensors/transducers have their place as well. But a scope is not the holy grail of automotive tools or diagnostic equipment, IMO. A lot of people are too young to know that we were using scopes 40 plus years ago. Anyone remember the sun or the bear scope, just to name a couple? Anyway, the best tool you can use for diagnostics or all around automotive repair is the one above your shoulders, it also comes in handy for getting through life in general! Peace and respect to all. 🙏🏼
Agree, its not my go to right off the bat. Was just suggesting to show how a differnt use case of the scope, I work on large industrial power gen equipment . Some diesel engines running natural gas. Some models have one head per cyl. In that case its proved very helpful in isolating the specific head.
@@jessemackenzie6516 And that's totally cool. We have to do whatever works for us in any given situation. I also wasn't trying to say anything negative about your comment either. You keep doing what works for you. 👍🏼
Same thing just happened to me with a brand new motorad thermo.. completely stuck out of the box just absurd.. seems to be the norm these days unfortunately
I use the vacuum adapter with the holes in it when I see consistent bubbles in the coolant or there is pressure in the system. I think the vacuum adapter with the holes in it allows pressure to escape. I know the radiator cap is used to pressurize the system in order to raise the boiling point. My question is this. Is it possible to get bubbles in the system from boiling a bit when the cap is off? I had an old Bronco that would constantly bubble and the test would always turn out negative for combustion gasses. It did it before and after changing the thermostat.Thanks for al the videos over the years. I've learned a lot.
Seems to me that having a squeeze bulb to draw the fluid in is better than connecting to a vacuum source for a number of reasons. I have to admit that I've purchased some of those cheap Lisle tools myself over the years. Some are ok, and some seem to have been designed by engineers who dropped out of school too soon. I can't believe how cold it is there, looks like some snow on the camera. Here in southern Arizona it's still getting up close to 100 during the day, but of course that's normal for us. No, it's not climate change, it's been this way since 69 when I got here, and 100 years as the historical record shows before then. We get a little cooler and night during September but the days don't start cooling off until October.
I've seen vid's on how to tell water in the oil (blown head gasket) by using a little oil out of the pan or dipstick and heat it up. If it boils when heated there is water in the oil pan. I have seen where chemical tests have shown all good but has been proven wrong by the above method as per Matt "Schrodingers Box".
The chemical kit is not 100%, neither is the water in the oil test. Early stages of head gasket failure will pass that test too. The HC test using a gas analyzer is the only one I've been 100% with and no one had a gas analyzer anymore!
ive never seen anybody have trustworthy results with one of these kits. I was going to mention gas analyzers but you talked about that not really being an option anymore. So whats the answer? Pressure test with a rad pressure tester? Maybe in combo with a compression test? (edit) I should have read thru the comments first-you talked about compression tests not really being reliable either.
You should do a compression test and also a Lead down test to find out the head gasket is leaking intake or exhaust . Could be a bad thermostat not opening ?
There are many times you'll have no bubbles, no milkiness in the oil. Also, you can't really check for bubbles on a overheating condition as boiling makes bubbles. If it was as simple as checking for bubbles only, do you think they'd even make kits like this?
Is there anything that would cause a false positive on the block test? I've seen vehicles with no symptoms of overheating or head gasket failure, even vehicles that just had the head gaskets replaced, and the block test tests positive.
false positive maybe due to old solution absorbed so much atm CO2 already, just a little more sucking of radiator's regular air causes the tipping point? False negative may mean the HG leak is so small that tester will take a longer than normal time for the concentration of CO2 to tip the ph scale color change? Like u say, better have another test to substantiate, same reason a doctor tests ur urine and blood at the same time.@@ScannerDanner
Compression test? There was no compression test done. It is also not uncommon for a compression and leak down test to completely pass with a head gasket leak
The accuracy of this test can be misleading. I have seen in the past head gasket failure, but would only overheat with the cooling system under pressure. This test works well when head gasket has completely failed. Sometimes if the head gasket is slightly compromised, but has not failed completely this test can be inaccurate. The best test in my opinion would be to pressure test the cooling system, and check for leaks, and pressure loss. If no external leaks are found, then using a bore scope down the spark plug holes to check for coolant works well. Leak down testing can yield favorable results as well when trying to track down a bad head gasket.
The radiator cap is no good. You can see it's missing the center plunger that controls flow from the overflow tank to the radiator and back. That will cause it to spit fluid out and overheat.
@ScannerDanner That radiator cap is still bad regardless. It's missing the center plunger, that's why when you squeezed the upper radiator hose with the cap on it shot coolant into the overflow container.
This was an actual overheat and the cooling fans were running constantly with cold air coming out of the radiator. So definitely not the symptoms of a bad coolant sensor. In those cases the fan may not come on at all
No, carbon dioxide. The fluid changes color in the presence of carbon dioxide. Even though engines do produce some carbon monoxide, most of what comes out the exhaust is carbon dioxide and water vapor.
Carbon dioxide. That's why you can test the fluid just by using your breath to make it turn yellow, a good way to confirm the fluid is working properly to detect CO2. Also by allowing the vacuum to draw fresh air back through the fluid, the fluid can be reset/returned back to blue, and then it's ready to be reused👍
Good question. Have you ever seen what these ignition timing maps look like? It's crazy. They are all over the place! Sometimes timing is late to help heat up the catalytic converter faster. I'm sure there are other reasons for it too that I cannot answer.
How did you get a false positive? Old fluid? I always test the fluid first with my breath. False negative for sure. But I've never seen a False positive. Thanks! Any additional info you can share would be great.
Never was a big fan of those chemical block testers. Not 100% reliable for testing a blown head gasket. Those things work only if the combustion gsses get into the cooling system which doesn't happen every time. A lot of times the blown head gasket will at as a one way check valve allowing coolant to be sucked into combustion chamber to be burt off but not allow gases into the cooling system.
I caught myself smelling maple syrup.... I'm glad when it's just the radiator. When a head gasket fails only under load, pressure transducer on the radiator and cyl #1 sync. Then give it some hard pulls.
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