Onan 10KW QD Generator - Radiator

[Newcsn]

Did a walk-around while visiting our 2006 Dynasty D4 the other day & noticed a wet spot under our genset. Crawled under & it appears to be leaking from the passenger side of the radiator. I removed some of the shroud & the coolant reservoir to see if it the plastic reservoir was cracked - no cracks & no visible hose leaks. Upon closer inspection it appears it's either leaking from the side tank seal (between side tank & core) or the core tubes (looks to be an aluminum core).

Has anyone encountered this before? It appears the radiator is a side load w/ an access panel on the passenger side of the genset. However, it appears the genset will have to be lifted about 6" in order to remove the radiator - the hydraulic slide out cylinders/mount are in the way.

Thanks for your feedback!

[Frank McElroy]

I can't recall any posts, at least not recently, where someone had to replace the radiator on a 10KW generator.  If you don't already have the service manual showing how to replace the radiator, there should be one in our downloads files.  If you need it and can't find it, let me know and I'll send you a link.

[Newcsn]

@Frank McElroy Thanks for the feedback! Sorry for the delayed response - have been traveling & unable to do additional diagnostics on the genset coolant leak. I’m very pleased to say the radiator appears to have not been the problem! When I removed the radiator side access panel it appears the radiator hose clamp needed some tightening. Gonna keep an eye on it - but I think we’re good for the time being! Thanks again 

[Steven P]

At the coldest temp my coach has seen this winter, I had a small amt of coolant under the Radiator (it had not been running).  I've kept an eye on it and none since, but it has not sat outside in the 20s again.  I'm hoping mine was just not used to the cold and had some "shrinkage" somewhere. 😅

[Newcsn]

@Steven P Great observation - I’m wondering if ours was a similar situation. Since we’ve owned it, it’s never sat outside & experienced cold temps near what we had in December - it got to 9 elbow for an extended period here in Indy. Hoping that’s it! Thanks 

[Bruce S]

We did have a leak in our Onan 12.5K QD when purchased.  The ends of the radiator were plastic which meant replacement only.  At the time I was quoted $2400 for the part so I removed the old one and took it to a local radiator shop and they fabricated one out of metal for about $500.  The only issue I had was that the replacement was about 1/8" thicker than the old one.  This meant enlarging the opening on the side where the radiator slips in/out.  

[96 EVO]

2 hours ago, Bruce S said:

We did have a leak in our Onan 12.5K QD when purchased.  The ends of the radiator were plastic which meant replacement only.  At the time I was quoted $2400 for the part so I removed the old one and took it to a local radiator shop and they fabricated one out of metal for about $500.  The only issue I had was that the replacement was about 1/8" thicker than the old one.  This meant enlarging the opening on the side where the radiator slips in/out.  

First time I've heard of one leaking!

Didn't get struck by anything?

[Bruce S]

The fins were pretty battered so I expect the previous owner must have done something especially since the radiator sits right at the front in a horizontal position.  He might have hit some wildlife...  I did a lot of work on this generator when we got it home including replacing the main control card.  Runs like a top now....lol

[96 EVO]

I once had a stare down with a turkey that was crossing the interstate and decided to stop in the middle of my lane 😮!

I was doing about 70, passing a semi, and had a line of traffic barreling up behind me, so slamming on the brakes was out of the question! All I could think of was 'there goes my front fiberglass'!!

Last second, he reversed course, and returned to the center median.

[Twomed]

I did a radiator on a 7.5... when I got it apart it had a Modine part number.

$89 vs $335 from Onan...several years back.  Arrrgh...Pirates!

 

[96 EVO]

I'm surprised Onan was only asking $335!

Think they want over$200 for their junk, leaky plastic overflow tanks!

[Newcsn]

Attempting to be prepared for “the worst”, I explored the cost of a Cummins & aftermarket radiators for our 10KW QD.  Cummins = ~$2000 - Aftermarket = ~$1200 and both on back order. I spoke with a gentleman who replaced his 12.5KW radiator with a 79 VW Rabbit aftermarket radiator. Said it was almost an exact replacement for about $150 - and they’re available all over the place - said the radiator’s side drain aligned perfectly with the hole in the lower generator chassis.