[2009lowrider]

Independent shop diagnosed blown head gasket but there is no oil leak on my 2009 Dyna Low Rider. Is that possible?

I took it to a small Dyno tuner shop near where I just moved to (so I don't know anyone for hundreds of miles around) and the guy called me a while after I dropped it off for the tune and told me to come back because there is a problem he wanted to show me.

He had my bike warmed up and let me use his stethoscope to listen to engine where head meets jug on left side and then on right side. I heard the difference, kind of an on-and-off tweeting or whistling, and I could hear it a little without the stethoscope.

There is no oil leak or any visual indication of a problem. The bike doesn't seem to have lost power but it sometimes seems a bit off, like needing tune (it currently has FP3 which was last adjusted over a year ago).

I'm no expert and only been riding 4 years and am 61 and never road even a dirt bike before 57 years old. I wrenched on cars over 3 decades ago but probably forgot more than I ever knew.

It doesn't seem to have lost compression either and I have a Innova cheapo compression tester that I will check again after doing it wrong the first time by leaving air filter and air cleaner cover on. Both front and back cylinders read 190 doing it wrong like that if that info means anything of value. I will remove filter and check again as soon as I have no rain long enough to do a warm-up ride before the test today.

In the mean time, any helpful info would be appreciated. I am wondering if I am just being taken for a fool (and a lot of money) because later I started wondering if I was just hearing normal exhaust or intake noise with stethoscope checking cylinder head at gasket on that side of engine where everything seems close to exhaust and intake noise.

Thank in advance.

 

[2009lowrider]

P.S. Also related to my first post about my head gaskets, I went and bought my own stethoscope from Northern Tool + Equipment and hear no whistling/tweeting, just louder noise closer to intake and exhaust.

 

[wonkey]

Do a leak down test, you can buy a test kit on line, they are not that much. The noise could be coming from the exhaust port.

 

[2009lowrider]

Do a leak down test, you can buy a test kit on line, they are not that much. The noise could be coming from the exhaust port.

I just checked the plugs and noticed the dyno tune guy who put them in gapped them at 0.049. WTF is with that?! Can you think of any reason other than him sabotaging my bike?

 

[sardonicus87]

Leaving the air filter on isn't wrong as far as I know, but you do want the throttle wide open and the enrichner wide open (turn the fuel supply valve off), and you want to do it on a fully warmed up engine.

Yes, it is possible to have a head gasket leak without having any oil leak with it or other visual signs, especially if it happens to be a pretty small/minor leak.

A compression test can kind of give you an idea if you even need to bother with a leak-down test. Just watch the needle, it should be at the full PSI in like, 3-5 strokes or so and once it stops moving, it shouldn't be jumping too much and it shouldn't fall much between strokes on its way up. Also, the first stroke should jump the needle most of the way, so if the final PSI is 190, it should be like 170 on the first stroke or something.

If a compression test indicates something not right (doesn't reach as high a PSI as it should, takes too long to reach full compression, low PSI on first stroke, cylinders not within 5 or 10% of each other, etc), then a leak down test can tell you exactly what's wrong.

If you hear the whistling on the right side but not the left, I wouldn't rule out a possible exhaust leak as per the last poster.

 

[2009lowrider]

Leaving the air filter on isn't wrong as far as I know, but you do want the throttle wide open and the enrichner wide open (turn the fuel supply valve off), and you want to do it on a warm engine.

Yes, it is possible to have a head gasket leak without having any oil leak with it or other signs if it happens to be a pretty small/minor leak.

A compression test can kind of give you an idea if you even need to bother with a leak-down test. Just watch the needle, it should be at the full PSI in like, 3-5 strokes or so and once it stops moving, it shouldn't be jumping too much and it shouldn't fall much between strokes on its way up.

I did have the throttle wide open. I got some of it right, lol. I don't have fuel supply valve that I know of. I have the fuse for the pump in the tank or just unplug it but it didn't blow up when I cranked it with just the plugs out and plug wires removed at coil.

Leaving the air filter on isn't wrong as far as I know, but you do want the throttle wide open and the enrichner wide open (turn the fuel supply valve off), and you want to do it on a warm engine.

Yes, it is possible to have a head gasket leak without having any oil leak with it or other signs if it happens to be a pretty small/minor leak.

A compression test can kind of give you an idea if you even need to bother with a leak-down test. Just watch the needle, it should be at the full PSI in like, 3-5 strokes or so and once it stops moving, it shouldn't be jumping too much and it shouldn't fall much between strokes on its way up.

What is enricher? I haven't read anything about that being on my bike.

 

[2009lowrider]

I did have the throttle wide open. I got some of it right, lol. I don't have fuel supply valve that I know of. I have the fuse for the pump in the tank or just unplug it but it didn't blow up when I cranked it with just the plugs out and plug wires removed at coil.

What is enricher? I haven't read anything about that being on my bike.

Leaving the air filter on isn't wrong as far as I know, but you do want the throttle wide open and the enrichner wide open (turn the fuel supply valve off), and you want to do it on a warm engine.

Yes, it is possible to have a head gasket leak without having any oil leak with it or other signs if it happens to be a pretty small/minor leak.

A compression test can kind of give you an idea if you even need to bother with a leak-down test. Just watch the needle, it should be at the full PSI in like, 3-5 strokes or so and once it stops moving, it shouldn't be jumping too much and it shouldn't fall much between strokes on its way up.

I'm going to give it a try again soon. I was starting to and pulled my spark plugs again and took a closer look at them because the dyno tune guy who told me about the head leak had sold me plugs and fancy Nology Hot Wires that he installed right before I took the bike home after he told me about head gasket leak. He doesn't do that kind of wrenching anymore, he's 70 and only does the tunes, and I had to take the bike somewhere in same town to a independent shop he knows so I have to wait for him to work on it but already gave him parts money.

Anyway, while I'm stuck not being able to ride except to take it to shop, I thought I'd get the compression tester because something seemed hinky. That led me to this other stuff and when I looked closer at the plugs—actually it stands out like sore thumbs— I noticed the gap is wider than I've ever seen on any vehicle. The end is bent out noticeably far past 90 degee angle to the plug body. I checked the gap and he has them at 0.049 while Harley manual says max of 0.042!

Ever hear of that? Is he trying to sabotage my bike?

 

[sardonicus87]

I did have the throttle wide open. I got some of it right, lol. I don't have fuel supply valve that I know of. I have the fuse for the pump in the tank or just unplug it but it didn't blow up when I cranked it with just the plugs out and plug wires removed at coil.

What is enricher? I haven't read anything about that being on my bike.

Shit sorry, you won't have an enrichner if you have EFI, only carbs have enrichners (or chokes, depends on carb setup).

Anyway, compression test might be slightly different for EFI (especially if it's throttle-by-wire instead of a cable throttle). Double check service manual.

 

[2009lowrider]

Shit sorry, you won't have an enrichner if you have EFI, only carbs have enrichners (or chokes, depends on carb setup).

Anyway, compression test might be slightly different for EFI. Double check service manual.

Yeah, I checked manual. Even it is confusing because it says to take off the air cleaner when I'm pretty sure what they mean is only the cover and filter.

Can I do a cold test or does it really make a difference in accuracy having engine at operating temp? I would think heat expands and might make a leak harder to detect when checking compression?

 

[2009lowrider]

Leaving the air filter on isn't wrong as far as I know, but you do want the throttle wide open and the enrichner wide open (turn the fuel supply valve off), and you want to do it on a fully warmed up engine.

Yes, it is possible to have a head gasket leak without having any oil leak with it or other visual signs, especially if it happens to be a pretty small/minor leak.

A compression test can kind of give you an idea if you even need to bother with a leak-down test. Just watch the needle, it should be at the full PSI in like, 3-5 strokes or so and once it stops moving, it shouldn't be jumping too much and it shouldn't fall much between strokes on its way up. Also, the first stroke should jump the needle most of the way, so if the final PSI is 190, it should be like 170 on the first stroke or something.

If a compression test indicates something not right (doesn't reach as high a PSI as it should, takes too long to reach full compression, low PSI on first stroke, cylinders not within 5 or 10% of each other, etc), then a leak down test can tell you exactly what's wrong.

If you hear the whistling on the right side but not the left, I wouldn't rule out a possible exhaust leak as per the last poster.

I did compression test again. It went from close to 120 on first cycle to 190 by the 4th or 5th.

 

[2009lowrider]

I did compression test again. It went from close to 120 on first cycle to 190 by the 4th or 5th.

Actually maybe 190 by 3rd compression. I'm old, can't remember that critically except to say I didn't think there was anything wrong from the test.