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912S Gremlin, Advice needed and a lesson learne

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rjdaugh(at)rapidnet.com
Guest

Posted: Mon Jan 02, 2006 3:42 pm Post subject: 912S Gremlin, Advice needed and a lesson learne



Returning home after a ride, we had just touched down and I noticed some

splashes on the windshield. (This is not good!) Since the temperatures

were all still good, I taxied on over to the hangar and my friend helped me

pull the cowl off.

By this time, we had identified the splashes as anti-freeze. I was

expecting to see some hose connection leaking, but all fittings were fine,

but the cowl above the overflow container was wet with Dexron. All the

fittings were dry. As we watched, the engine cooled and started sucking the

coolant back into the engine. I added between 32 and 39 oz. of 50/50 before

it all quit sucking back into the engine. This took several hours. This

still left the level in the overflow container near the minimum level.

My friend says that I just had too much fluid in the overflow container and

it flowed out as the engine warmed up. I don't buy this because; 1) I

haven't added anti-freeze over the whole 87.2 hours of flying prior to this

happening. 2) If this was just normal expansion, I would not have had to

add any additional coolant as the engine cooled. 3) I don't think it would

have put coolant all over the top cowl above the overflow container -

Although the air flow in the cowl may splash it around a good bit.

Anyway, I feel that somewhere (one head?) something was hot enough to boil

the coolant and that is what blew stuff out the top of the overflow. My

guess is that the flow to one head wasn't up to snuff and that caused the

problem. I have taken the hoses off the bottom of all the heads and blown

air down backwards through the head and can't detect any restriction in any

of the heads. I would feel much better if I could find a reason for this

blooping of coolant.

I should mention that I have a Grand Rapids EIS that tracks the head temps

on two heads - neither those nor the oil temp was too high. About 2.8 hours

of flying time before this flight, I had covered about 1/3rd of the radiator

surface to try to raise temps during winter flying. After doing this, I

climbed to 10,000 ft to watch temps and they were fine as they were for more

than 2 hours before this last flight. I don't think that covering part of

the radiator was a major cause, but of course it could have aggravated the

situation.

Any advice would be appreciated.

Lesson Learned

I was really worried for some time because as the engine was cooling and I

was adding 50/50 coolant, I decided to check the oil level. I was surprised

to see it near the top of the tank and decided that I had found where all

the coolant that I was adding was going. But later found NO coolant in the

oil and the oil level was Normal! (My panic was unjustified!)

Lesson? Check your levels when the engine is hot, so you will know what to

expect. I wish that I knew what the level in the over flow container should

be when the engine is hot.

Thanks for listening and tell me what I may be missing.

Randy - Series 5/7 - 912S

.

aldaniels(at)fmtc.com
Guest

Posted: Mon Jan 02, 2006 4:30 pm Post subject: 912S Gremlin, Advice needed and a lesson learne



Two things to check. #1 Did you increase the size of the overflow tank

cap vent hole. I don't understand why this causes a problem but was

warned that it might. #2 Check to see if the return hose going to the

water pump shows signs of collapse. We had one that would suck shut when

it got hot and cause coolant to blow out the overflow tank. This

probably is not the problem because it would show up as high

head/coolant temp but check it anyway. On a 7 Firewall Forward if you

use the provided hose I think is in real risk of collapse due to the

bend around the engine mount. I use a molded hose from NAPA that has

solved the problem.

Randy Daughenbaugh wrote:

Returning home after a ride, we had just touched down and I noticed some

splashes on the windshield. (This is not good!) Since the temperatures

were all still good, I taxied on over to the hangar and my friend helped me

pull the cowl off.

shoeless(at)barefootpilot
Guest

Posted: Mon Jan 02, 2006 4:47 pm Post subject: 912S Gremlin, Advice needed and a lesson learne



Randy,

Do you have cabin heat that uses hot water?

If so, do you have a control valve to turn flow on and off to the heater

core?

It's possible with this type heater to have an air bubble in the system that

has been sitting there waiting for the most inoportune time to work it's way

into the engine. If this happens it would rapidly expand and blow a bunch of

coolant out into the bottle....

You can guess how I know about this...

Best Regards,

Cliff

 	  Quote: 	
		  

Returning home after a ride, we had just touched down and I noticed some

splashes on the windshield. (This is not good!) Since the temperatures

were all still good, I taxied on over to the hangar and my friend helped

me

pull the cowl off.

By this time, we had identified the splashes as anti-freeze. I was

expecting to see some hose connection leaking, but all fittings were fine,

but the cowl above the overflow container was wet with Dexron. All the

fittings were dry. As we watched, the engine cooled and started sucking

the

coolant back into the engine. I added between 32 and 39 oz. of 50/50

before

it all quit sucking back into the engine. This took several hours. This

still left the level in the overflow container near the minimum level.

My friend says that I just had too much fluid in the overflow container

and

it flowed out as the engine warmed up. I don't buy this because; 1) I

haven't added anti-freeze over the whole 87.2 hours of flying prior to

this

happening. 2) If this was just normal expansion, I would not have had to

add any additional coolant as the engine cooled. 3) I don't think it

would

have put coolant all over the top cowl above the overflow container -

Although the air flow in the cowl may splash it around a good bit.

Anyway, I feel that somewhere (one head?) something was hot enough to boil

the coolant and that is what blew stuff out the top of the overflow. My

guess is that the flow to one head wasn't up to snuff and that caused the

problem. I have taken the hoses off the bottom of all the heads and

blown

air down backwards through the head and can't detect any restriction in

any

of the heads. I would feel much better if I could find a reason for this

blooping of coolant.

I should mention that I have a Grand Rapids EIS that tracks the head temps

on two heads - neither those nor the oil temp was too high. About 2.8

hours

of flying time before this flight, I had covered about 1/3rd of the

radiator

surface to try to raise temps during winter flying. After doing this, I

climbed to 10,000 ft to watch temps and they were fine as they were for

more

than 2 hours before this last flight. I don't think that covering part of

the radiator was a major cause, but of course it could have aggravated the

situation.

Any advice would be appreciated.

Lesson Learned

I was really worried for some time because as the engine was cooling and I

was adding 50/50 coolant, I decided to check the oil level. I was

surprised

to see it near the top of the tank and decided that I had found where all

the coolant that I was adding was going. But later found NO coolant in

the

oil and the oil level was Normal! (My panic was unjustified!)

Lesson? Check your levels when the engine is hot, so you will know what

to

expect. I wish that I knew what the level in the over flow container

should

be when the engine is hot.

Thanks for listening and tell me what I may be missing.

Randy - Series 5/7 - 912S

.

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jdmcbean(at)cableone.net
Guest

Posted: Mon Jan 02, 2006 8:36 pm Post subject: 912S Gremlin, Advice needed and a lesson learne



Randy,

Most likely had an air bubble in the system... another thing to check is

the location of the Overflow bottle.. should be lower then the expansion

tank. Check the hole in the cap as well.. I believe there was a service

bulletin on that issue.

Have a Safe New Year !!

John & Debra McBean

www.sportplanellc.com

"The Sky is not the Limit... It's a Playground"

rjdaugh(at)rapidnet.com
Guest

Posted: Tue Jan 03, 2006 8:13 am Post subject: 912S Gremlin, Advice needed and a lesson learne



Thanks Alan, - I have been watching an incipient kink on the other side of

the radiator. I should be more concerned about the suction side of the

pump. The molded hose is a great suggestion. The size of the hole in the

cap of the overflow tank doesn't make sense to me, but it is the stock cap.

Thanks Cliff, - The air bubble seems to fit all the data. I do have a

heater core in the cabin - it was used last winter and this fall. (?) But

we had been doing some extreme slips.

Thanks Sid, - I plan to spend some more time with that website.

Thanks John, - I think I have the overflow tank in the correct place, and

will investigate the hole in the cap.

This list is great!

Randy

.

Malcolmbru(at)AOL.COM
Guest

Posted: Tue Jan 03, 2006 10:04 am Post subject: 912S Gremlin, Advice needed and a lesson learne



U should go to kodiacbs.com mal

kitfoxjunky(at)decisionla
Guest

Posted: Tue Jan 03, 2006 1:31 pm Post subject: 912S Gremlin, Advice needed and a lesson learne



How cold does it get where you are? How long had the plane been sitting?

I had my plane in storage last year in an unheated hanger. I noticed some

coolant was leaking from the fitting that goes into the cyl head..on more

than one cylinder. Not a lot..just a few drops on the floor. Someone

knowledgeable with snowmobiles told me that is common. A few weeks back I

went out and noticed the same thing. I ran the engine up and kept a close

eye on it. Once it came up to temp it seemed fine. When I put it way

there was no sign of a leak. Went back a few days later when it was very

cold and again noticed some coolant in the same spot.

Sounds like you had a lot more than a few drops showing..so probably not

the same thing..but thought it was worth mentioning.

Anyone else notice this type of thing with the 912 series of engines when

they cold soak for awhile?

Gary Walsh

KF IV Anphib 912S

C-GOOT

www.decisionlabs.com/kitfox

do not archive

"Randy Daughenbaugh" <rjdaugh(at)rapidnet.com>

Sent by: owner-kitfox-list-server(at)matronics.com

01/02/2006 06:42 PM

Please respond to kitfox-list

temco(at)telusplanet.net
Guest

Posted: Tue Jan 03, 2006 1:57 pm Post subject: 912S Gremlin, Advice needed and a lesson learne



Mal

Not sure what you're driving at here --- tried to access the site you

mention and no go. Could you explain further. Thanks

Ted

Edmonton, Ab

DO NOT ARCHIVE

----------------SNIP---------------

Subject: Re: Kitfox-List: 912S Gremlin, Advice needed and a lesson learned.

U should go to kodiacbs.com mal

kirk(at)mninter.net
Guest

Posted: Tue Jan 03, 2006 8:13 pm Post subject: 912S Gremlin, Advice needed and a lesson learne



I have a pan under my Kitfox. The water pump leaks a small puddle when it

gets cold. When I run up the engine and the seals heat up, no more leak.

After a day or two in cold weather, same thing. It has been like that since

I got the plane running in 2000.

Kirk Martenson

Classic IV Rotax 912 UL

jimshumaker(at)sbcglobal.
Guest

Posted: Tue Jan 03, 2006 11:16 pm Post subject: 912S Gremlin, Advice needed and a lesson learne



Gary

rjdaugh(at)rapidnet.com
Guest

Posted: Wed Jan 04, 2006 5:53 am Post subject: 912S Gremlin, Advice needed and a lesson learne



Gary,

I haven't noticed any leaking at where the fittings go into the heads. How

do those fittings go in? Are they cast in?

I have had problems with the screw type hose clamps. I tighten them in warm

weather and they work great, but when it gets cold (teens F here) they all

seem loose and some dribble a bit. I tighten them and then when warm

weather returns the rubber in the hose expands and the clamps really cut

into the hose. - The clamps seem too tight at that point. I don't see any

of this type behavior with the spring clamps supplied by Rotax. Perhaps

they can expand and contract to keep the right compression on the hose.

But this is different than my most recent problem. I lost a quart of

coolant in short order in what ever happened.

Randy

.

lcfitt(at)sbcglobal.net
Guest

Posted: Wed Jan 04, 2006 7:27 am Post subject: 912S Gremlin, Advice needed and a lesson learne



Kirk,

I talked to a Rotax Rep about the same problem and they suggested BarsLeak.

I tried it and it worked.

Lowell

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