[larolco]

Desertbike, was that you who posted elsewhere about exhaust dents, or am I misremembering?

I happened to be under mine this weekend swapping out chain and sprockets and had a look. There is a factory dent on the kickstand side to allow for the OEM center stand, but there is no indentation on the other side. So, I do believe you have dented your pipe.

I also think you should not worry about it since there is an almost identical one, factory-installed, just a few inches away.

 

[DesertBike]

Yep that was me. I'm just going to leave it be. No impact to fuel economy seems apparent. I got 44 mpg on my last tank (it helps to stay off the interstate!).

The most likely culprit for the extra dent would have to be a rock. Before the skid plate, I did a fair amount of riding on rocky dirt roads. Can't remember bottoming out the suspension hard enough to do something like that but who knows?

If the extra dent were caused by a rock though, I would expect it to not be so gently curved. You'd think a sharp rock would have almost punched a hole in the metal or at least creased or scratched it. Go figure.

 

[DesertBike]

Another short-ish ride this morning. No drips so far.

 

[87Duckfan]

Parts Diagram?

Does anyone have a diagram of where this thermostat housing is located?

Before, it looked like I wasn't getting any leaks, but the working theory now is that I get a drippy thermostat housing until the engine warms up sufficiently.

I went for a long-ish ride over the weekend & got home with no evidence of leakage.

T-stat housing bolt torque checked. Service manual calls for only 7.0 lb-ft which is basically "hand-tight."

If the T-stat housing only seals properly once the engine is hot and stays there, that would account for the dripping I've been seeing on more recent, very short rides, and the lack of evidence of leakage after longer rides.

I'm sick of dealing with this, so I've put a bead of RTV (Permatex Optimum Grey) on the seam of the thermostat housing. Giving it a full 24 hours to cure before I ride again. We'll see whether it does anything.

 

[larolco]

It's between the cylinder heads, beneath the throttle bodies.

See it here: https://www.partsfish.com/oemparts/a/suz/508afc4ff870023530722f92/radiator-hose

 

[DesertBike]

Inevitably, some evidence of leakage, but it's so slight that I couldn't figure out where it was coming from.

Happened after a very short (<5 minutes total engine run time) ride.

At least I'm pretty sure it was coolant. Felt greasy like coolant does, but there wasn't enough to get a good look and I certainly wasn't going to taste it.

I guess I'll call that a win? Previously I would get enough drippage to pool between the cylinder heads. Now I'm just getting one or two drops.

Still nothing on longer rides, so I guess there's that.

I give up. I'm not tearing the bike halfway apart to replace the coolant union O-rings (especially given I can't even trace the leakage there), but maybe I'll do them when I have the airbox off for something else, later this year.

 

[DesertBike]

Does anyone have a diagram of where this thermostat housing is located?

What he said, it's semi-hidden but not really, look from the left side of the bike and you can't miss it.

Based on my experience, I'd say don't bother replacing the thermostat, if you're having a drip like mine. Not worth the $ or effort, as the thermostat is probably fine.

If you are having the same problem I was, you might try the RTV gasket maker first. It has almost completely solved the problem, with no apparent ill effects.

It seems the thermostat housing is just inevitably going to leak if it doesn't get warm enough, as on very short rides.

 

[DesertBike]

update to the update: I slathered on some more RTV, double-coating the area that was visibly dripping & extending the "gasket" a bit. Gave it a full 24 hours to cure.

Fingers crossed, no more drips so far.

If I can't 100% eliminate the drips I guess I can live with it. Leakage is greatly reduced vs. before applying the RTV gasket maker, and doesn't seem to happen at all as long as I ride more than ~5 minutes.

 

[V-Tom]

At least I'm pretty sure it was coolant. Felt greasy like coolant does, but there wasn't enough to get a good look and I certainly wasn't going to taste it...

How is your (clutch) slave cylinder doing?

..Tom

 

[DesertBike]

Clutch slave is just dandy. Amazingly I have managed not to break it, put it back on crooked, or forget the supporting sleeve on the one bolt (upper?) in the last several removals & replacements.

 

[V-Tom]

Clutch slave is just dandy. Amazingly I have managed not to break it, put it back on crooked, or forget the supporting sleeve on the one bolt (upper?) in the last several removals & replacements.

Yeah forgetting the sleave/spacer was why I broke my first one.

You seemed unsure if the coolant drip was actually coolant. With it coming from the left side I wondered if it might be fluid from a leaky slave cylinder.

..Tom

 

[DesertBike]

No that was definitely coolant.

It would be just about impossible for brake fluid to get up in the vee of the engine & drip down. Also it smells different.

 

[DesertBike]

Ugh, I was STILL getting some drips despite the RTV.

I applied more RTV. Seems to have stopped the drips again, at least temporarily.

It's possible that while I've stopped leakage through the bottom seam of the thermostat housing, the coolant is just leaking out of the top seam instead. I couldn't get RTV up there without smearing it all over lots of other stuff & making a huge mess, so I didn't try.

I now have some different RTV, designed specifically for coolant system sealing. The next time I have the tank and airbox off, I'll clean off the gray RTV & put a bead of the "water pump" RTV between the thermostat housing halves.

 

[DesertBike]

Well, that didn't last long. Got a nice half-or-so ounce of coolant on the ground when I stopped a few minutes into my morning commute.

Going to move some stuff out of the way, drain coolant and seal that housing up properly this weekend. I'll make a gasket with Permatex Water Pump RTV, since the gasket built into the thermostat isn't doing the job.

 

[DesertBike]

Got to it over the weekend.

Nearly all of the old RTV peeled off the T-stat housing easily. Not surprising I still had a leak. There's no way to get a proper seal by applying RTV from the outside. It has to get sandwiched between the metal faces of the housing halves.

Water pump RTV applied, thermostat reinstalled, housing bolted back on, radiator pipe reattached, then 24 hours to cure before refilling coolant.

The next day, coolant went back in, then a test run up to 3 bars on the temperature gage. No leaking so far, but a test ride will tell the tale for sure.

In the service manual, I noticed that the thermostat jiggle valve (little sheetmetal thingy near the rubber gasket) is supposed to be at the top, or 12 o'clock position. Not sure how I had it before, or how it was oriented when I swapped the thermostat several months ago. Could incorrect position somehow have caused the leaking? Seems unlikely - but hard to be sure.

Here's more info than you ever wanted to know about thermostats, including jiggle valves:

https://www.hemmings.com/blog/article/some-like-it-hot/

Stant states the purpose of the jiggle valve is to faciliate purging of air from the system:

Stant

 

[DesertBike]

Test ride yesterday showed no evidence of leaking. But, I thought that before - won't know for sure until I have several commutes done. Typically, the leaking was most evident in my morning commute.

I am not a fan of the service manual's method for purging air after a coolant change/refill. I cannot physically manage to both rock the bike back and forth, AND tap on the thermostat housing. At least not safely, working solo. What's worked for me is a series of short rides. Once I shut down, the cooling system will then expel air and suck down whatever's in the reservoir tank. Repeat and refill until the level in the tank doesn't change.

 

[DesertBike]

Another two commutes down, no evidence of leakage.

Usually I could smell the hot coolant, even if I couldn't see it dripping. No smell, no streaks of dried coolant on the engine case after I got home, fingers crossed!

 

[DesertBike]

That didn't last long. Stupid thermostat housing started leaking again. Somehow, I missed tightening the housing bolts, or they worked loose on their own. Dunno how that happened. Could swear I tightened them.

I expect leakage resumed because the RTV isn't enough, on its own, to seal the thermostat housing. The housing has to be clamped together pretty tightly. RTV will only seal tiny, nearly invisble gaps where metal touches metal. The mating surfaces are machined pretty smooth, and you would think the rubber gasket on the thermostat itself would fill any gaps, but obviously not.

I re-did the whole job. Was super careful to get all surfaces clean, & let the RTV cure more than 24 hours before tightening bolts down. I'll be checking whether they are somehow loosening on their own & applying Loctite if required. No drips so far, fingers crossed (again!).

Worst part of the deal is having to drain and later refill coolant (and purge air). There's no neat way to do the draining.

I think I worked out what was happening in the first place. Coolant was leaking from the thermostat housing during "bypass" time, between start of a cold engine, and when it got hot enough to make the thermostat open. Leaks wouldn't happen at idle, but revving the engine raised coolant pressure enough to cause drips.

Also: once the engine is at operating temp (thermostat open) could be the metal of the housing expands enough to seal better. I've never seen evidence of leakage when the engine is already hot.

During my morning commute, coolant would drip for the first few minutes as I accelerated, but the thermostat hadn't yet opened.

Really hope this is now fixed for good. Don't know what else I can do.

 

[DesertBike]

Man, dunno how I missed this but apparently my problem may indicate a waterpump rebuild, or at least impeller replacement:

https://www.stromtrooper.com/maintenance-tech-products/40521-weird-coolant-leak-2.html

Joke's on Suzuki this time, because I ordered all the parts for a waterpump refresh about a year ago. Gasket, impeller, you name it, I've got all the fresh bits.

Of course, draining (and later refilling and getting air out) the coolant yet AGAIN will be a pain in the ass, but, whatever, I've got plenty of replacement coolant, and I'd rather fix 'er right.

 

[DesertBike]

Yet again, I find Black Lab Adventures did this job (on a DL650 though) several years ago, and am using the excellent writeup as a guide:

https://blacklabadventures.com/2012/02/22/rebuilding-the-water-pump/

First thing I had to do was, drain engine oil and coolant.

It was time for an oil change anyway, luckily. Got the old oil drained, filter swapped, oil drain plug reinstalled. Just have to remember to refill oil at the end.

Draining coolant was, as always, a messy pain in the butt. There's simply no way to drain coolant completely. You'll always have some "ullage" that falls out when you remove the water pump cover.

I got as far as removing the crankcase cover last night.


Some notable differences between my 2007 DL1000 and Barry's DL650:

-there is a large metal wall, aka "Oil Separator," attached to the inside of the crankcase cover. I suppose it keeps oil from splashing too much on the bearings & seals that keep oil away from the coolant system, and vice versa.

-This oil separator is held in by 4 large Philips-head screws. For some reason, mine were stuck HARD. I got exactly one of them to turn with just a screwdriver.

Tried an impact wrench, need a better Phillips-head bit. One screw hread is now a little boogered up. I'm going to replace all four screws with hex-heads. Purchasing a broken screw extractor, just in case.