Community Forums

dgerstel · 06-06-2009, 10:28 PM

Mike, at Cummins in Yakima, inspected my cooling system to find the possible source of my overheating problems. When he reached up, between the grill and the radiator air shield, he found a large gap. There were also gaps at the front, back and bottom. This allows the heated air in the engine compartment to re-circulate thru this gap and back thru the radiator again. This (re-circ) air shield was responsible for Alpines excellent cooling characteristics. He also informed me that he had seen quite a few Alpines leave the factory with these gaps. It appears to me that WRV has my radiator package mounted about 1" away from the grill, which accounts for most of the gap I had. Mike told me that WRV had some problems with the grill rubbing thru AC condenser. I assume that WRV moved the radiator back to give clearance between the AC condenser and the radiator and had not gotten around to re-designing the shield. Mike also pointed out the gap between the air charge cooler (turbo intercooler) and the radiator. This allows for the fan to suck in hot air thru this gap. He had requested that WRV mount these closer together to cut down this air path.

Better angle to show amount of gap at top.

Radiator mounted in the inner hole on chassis mounting arm.

Better shot of charge air and radiator gap.

I had the grill mounts fail and had seen these gaps after making new mounts. I was aware that this was not good but was not aware of the larger gaps on the sides and top. When I made my second set of grill mounts, long aluminum straps. I attached them to the inner fan shroud, instead of just the shield as was originally done. I also attached to the shield to these straps to hold it against the charge air cooler.

After many ideas on how to add seal to present seal, I came up with just adding sheet metal to present shield. This new strip extends past the sides of the intake grill and seals off the area pretty well.

I used rubber radiator hose, squeezed into the gap and held with silicone sealer to fill the gap between the air charge cooler and the radiator, front and rear. The rear shown above and below.

All of the photos were taken after I had moved the radiator package out at the bottom about 3/4", this was causing an even larger gap at the bottom.

On my trip from Yakima to Seattle, I found the cooling system to be much better. The real test will be in July on the trip home up Baker grade. I will report back after that run.

I have run into "air re-circ" issues in many instances in the past and had just not looked good enough at the area inside of my cooling air intake.
I would recommend that everyone check inside their radiator air intake grill. There should be NO gap between the air shield around the radiator and the air intake. Any sizable gap will cut down on your cooling efficiency.

Renipladlo · 06-06-2009, 11:43 PM

Dale, normally my engine runs around 180-190 F, rarely does it get above that temp. Even over the Siskiyou’s it only hit 195. The trans on the other hand on a long trip runs around 195-205 F, and I have seen it after a long run, then backcountry cool down, then backing into and around a RV park hit 220. The engine runs cool though, after a few minutes, it's down below 180.

OldForester · 06-07-2009, 10:50 AM

Dale,

What temperatures were you running on average before the shielding? Ours always runs in the low 190's, with occasionally up to 200-204 on a hot day and long steep grade, like the Pendleton, OR, Hill or the Grapevine in S. Cal when air temperature is 90 degrees or more. I'm just curious what you define as overheating?

dgerstel · 06-07-2009, 12:55 PM

I had talked to Mike Young about my overheating problems. He told me that the ISL had so much low end torque, that it would pull some hills at such a low rpm that the fan would not run fast enough for proper cooling. He had been involved in the design of the Alpine cooling system from the beginning. He stated that with the design used, any Alpine should be able to pull any hill in any weather condition, without backing off of the throttle, if the engine rpm was kept up in the 2,000 rpm range. On Baker grade I-15, after downshifting to keep rpm at 2k, speed about 55, engine would go to 115 and keep climbing. I would then have to down shift and let off of the throttle, to keep it below 115. On the trip up to Yakima thru Nevada, one of my readings was, 69 mph, 2k rpm, 895 lbs torque, 81 degrees outside and 215 degrees engine temp. After my fix, on the climb out of Yakima, going to Ellensburg, outside temp 82 degrees, pulling in cruise control, allowing trans to shift, never got over 203.

I was not insinuating that a lot of Alpines have this problem and it was not always a problem for me, just under some conditions. Mike Young made it very clear that he had seen both of the 2 conditions that were causing my problems on quite a few coaches. He had seen it on the production line and had made it clear to WRV that he thought it was a problem that needed to be fixed immediately. He then saw the gap between the grill and shield on some new coaches being displayed at a rally. He was very interested in getting this information out to all Alpine owners, so that everyone might check their own coach.

OldForester · 06-07-2009, 05:05 PM

Dale,

I assume you meant 215 and not 115 in the reply above. That is definitely higher than ours. I try to let ours run up hill in cruise control as much as possible and let it shift on its own. I usually take the tranny out of "economy" mode on the big hills so it will downshift more quickly. When I do that, it never gets above 205 as I said above, and often doesn't get above 200-202, so it sounds like you're now running in the same range as we are, but then we're probably about 3000 lbs lighter than you.

dgerstel · 06-08-2009, 08:43 AM

OldForester,

Yes to all. I will chastise my proof reader, oops, that's me. I would be concerned if it were running only at 115. New coach is at about 32,000 lbs, loaded + Honda van isn't light. I feel much better about how it runs now, but Baker grade in July will tell the whole tale.

Lindenberg · 06-09-2009, 10:04 AM

Do you have a photo or can you describe how your access panel with the radiator grill is secured along the bottom? On my 2000 a single screw broke that holds the lower front edge in place. I can't see an easy way to get a new screw to work in the same spot. I currently have some zip ties holding it closed until I come up with a better idea.

dgerstel · 06-09-2009, 01:50 PM

Tom,

My first replacements, were in the same area as in photo, but just to the air intake shied, about 3" long. This caused the shield to be pulled away from the radiator package. The new ones are mounted all the way back to the fan shroud, away from radiator, then to the shield and then the air intake grill. They are bolted to the bottom of the grill, between louvers, with carriage bolts, I will use touch up paint on the heads when I get home.

Lindenberg · 06-09-2009, 03:50 PM

Thanks Dale. A picture is worth a thousand words. I was focusing on making attachments near the ends of the panel door and didn't even think about using the access the louvers provided.

dgerstel · 06-09-2009, 04:02 PM

No problem Tom, I would rather post a photo than try to type an intelligible "how to do it." Then I have less questions to answer about things that I didn't post or describe well.

dgerstel · 06-22-2009, 11:07 AM

I think that when the new radiator was used, the charge air cooler and oil cooler could not be mounted right next to each other due to the bolt seen in the photo below. This is on an early 2007 coach that was built with the upgraded radiator, I haven't seen what the old radiator pack is like.

If this "new style" pack is wider than the older ones, then WRV would have to move the pack back from the grill to keep the AC condenser from hitting the grill. Photos of the gap on this coach.

I think that all "non-smog" coaches with the new radiator have this problem. It will probably only cause overheating problems on hot days and on long hills. It will probably cause the motor to always run hotter than coaches without the gap. This is from my experience.

NorCal Hal · 07-09-2009, 06:45 PM

GREAT Job Dale. Your description and photos made what would be impossible to describe in words only easy to understand!

Harold

EngineerMike · 07-09-2009, 07:21 PM

Based on this thread, an owner of an 34' 07 with the replacement radiator checked his. Sure enough he's got large enough gaps they probably explain his somewhat high temps (compared to average), and he is following Dale's lead to close the gaps.
Now if D.C. would just close a coupla gaps....

dgerstel · 08-10-2009, 09:13 AM

While this air flow fix did help, I am afraid that I still have some sort of overheating problem. I know that it is running hotter than I see others have posted. I can't find what is an OK temp to let it go to on hills at high air temps. The Silverleaf goes into the red at about the 220 degree range. I was told by Cummins that I needed to let it run up to where the engine overheat warning came on, so that they could see what the computer fault said. On the trip home I found that this doesn't happen until 235 degrees! I did have to run up the hill with the AC on and did not down shift to get it that high. I will now take it into Cummins to find out what the computer says.