persistant boiling problem

[SloJo]

My '06 955i has had a problem with boil-over ever since I was riding her down in the hot New Mexico desert last October. Having investigated the problem on numerous web-sites, I have done the following: 1. flushed and refilled with 50/50 antifreeze/distilled H2O. 2. bled air out of the cooling system by running the engine with the fuel tank removed. 3. replaced the radiator cap... twice! 4. replaced the thermostat. 5. checked the fan relay and fan fuse. 6. checked the fan itself by applying 12V to make sure it spins. 7. checked the coolant temperature sensor to make sure resistance values meet nominal specs both at room temp and at high temps. 8. checked that water pump is working by removing bleed screw from thermostat assembly while motor is running and getting coolant all over my face! After doing all this, when I run the motor at idle speed, the temperature gauge climbs to just above the lower mark for operational range, then after about 2-4 minutes, the coolant level rises from the Min mark all the way up and over, spilling out of the expansion tank. The fan never turns on under these conditions, but the temperature gauge never climbs that far, either: It stays well below the half-way mark. I fear a failed head gasket, but there isn't any steam coming out of the exhaust system when I start the bike after she has cooled down. Also, she still gets great mileage and power (as good as when I first bought her brand new), so I'm having a hard time believing I've got poor vacuum due to a blown head gasket.

Anyhow, I'm about to bring her to the dealer in Denver, but I thought I would give a shout-out to see if anyone had any more ideas before I hand her over to the mechanic with a blank check.

[JetdocX]

Fan switch working?  Jump the fan switch and see if the fan runs.  Does the same thing happen while the fan is running?

If it still is boiling over with the fan running, it's probably time to pull the head.

[SloJo]

Good idea. Unfortunately, after I built a little jumper wire to replace what I thought was the fan relay, I found out it wasn't the fan relay: My bike has only two relays located under the seat. I had previously assumed one of them is for the fan, so I had previously tested both relays to make sure they were working. Now, upon removing each relay and then attempting to start the bike, I discovered that one of the relays is for the ECM (bike is totally dead without it), the other is for the fuel pump (no sound of the fuel pump when powering up, and it won't catch when turning over the starter motor). My Haynes manual tells me that my version of the Tiger should not have either the fan or fuel pump relays, but the manual only covers Tigers up to 2005, so I guess Triumph revised the relay set once again for the '06 model and reinstalled the fuel pump relay... but not the fan relay.

When I'm riding on a level freeway, the boil-over doesn't occur. It only happens in stop-and-go city traffic or idling, so I think manual operation of the fan would have probably stopped the problem. But, that's obviously not a permanent solution...

[JetdocX]

Somewhere is a temp switch to turn the fan on.  Jump it.  The fan should run continuously.

[KuzzinKenny]

Don't know if this will be any help but.....

http://www.bikechatforums.com/viewtopic.php?t=140295

pinched from another site  :oops:

click on ( wiring diagram thread )

KK

[Mustang]

this is the pic from KK's link

it's pretty shitty quality


#52 is the fan and it is controlled by the ECM or ECU .

pull the plug on the connector to the fan and supply 12 volt + and ground to the fan .........if it runs then you have a bad sensor or the ECU itself is at fault

[wanderer505]

I had a similar problem on my '06, replace the radiator cap with a Napa cap, problem persisted.  Then ordered and installed a Triumph cap, problem went away.  Others have noted the same thing.  If the cap leaks, the system cannot maintain pressure and will boil over at lower temp.

[prbarr]

Like wanderer said, this sounds like a problem I had.  I posted this awhile ago.

http://tigertriple.com/forum/index.php/topic,7022&highlight=

[Timbox2]

Still sounds like an Air Lock or Faulty/Non OE Rad cap problem to me.

I changed my coolant recently, I went by the Haynes method which doesnt mention running the engine at all, what I have found is absolutely crucial is adding the coolant as slowly as possible, I took probably half an hour or more of adding little amounts slowly, letting it stand, shaking bike from side to side and squeezing hoses, at least twice the system at first seemed full, then would burp and the level drop right away again.

I changed my rad cap last year, and had to again this year, they dont seem to last that long, mind you it had done over 20k in that year.

[Chris Canning]

Still sounds like an Air Lock or Faulty/Non OE Rad cap problem to me.

I changed my coolant recently, I went by the Haynes method which doesnt mention running the engine at all, what I have found is absolutely crucial is adding the coolant as slowly as possible, I took probably half an hour or more of adding little amounts slowly, letting it stand, shaking bike from side to side and squeezing hoses, at least twice the system at first seemed full, then would burp and the level drop right away again.

I changed my rad cap last year, and had to again this year, they dont seem to last that long, mind you it had done over 20k in that year.

DITTO

[tett]

Did you ever solve this problem?  I now have the same problem.

Cheers,

mike tettenborn

[HockleyBoy]

Mine has been doing a similar thing for a while now despite collant changes, new cap etc and this morning disaster struck

http://tigertriple.com/forum/index.php/topic,11721

May or may not be connected, I will post more when I find out what the problem is.

[delecti]

the radiator cap failure will fill the overflow bottle and not allow the fluid back into cooling system when the bike cools down.

the triumph cap is not the same as the cap available in retail parts dealer it needs to be an orginal.

If the bike gets an airbubble at the themastat this will give the impression of the bike boiling as it makes the water temperate sensor to spike.

Mark