Community Forums

gramps66 · 07-30-2012, 07:37 AM

Wife and I are interested in an 2012 Monoco Knight with the maxforce engine. I heard that they have an overheating problem due to the nonuse of the exhaust gas fluid. That with the reburning of the exhuast gases that it makes overheating problems. That Holiday Rambler is thinking of revising there system. Any body eles here of such problems????????????????? .

Steve Ownby · 07-30-2012, 08:06 AM

I monitor several forums and have seen quite a few posts from owners of MF7 and MF10 engines. I don't think any were regarding overheating. I believe most of the posts concerned how MPG and power compared to others. I suspect if some one told you the MF engines were overheating, they were pushing something else.

Navistar is having a problem getting their 2 big engines the 13 & 15 approved by the EPA but the 7 & 10 seem to be working fine. The engines that use the exhaust fluid also have the exhaust gas recirculating system.

GaryKD · 07-30-2012, 10:04 AM

Hi gramps66,
I don't usually notice what goes on under the hood. However, in the case of Navistar, I would not purchase a coach unless it was using the DEF fluid to meet pollution requirements. Navistar recently announced they will also use the DEF technology to comply with pollution requirements. Navistar engines currently on the road not using DEF may become "white elephants". Why take the chance?

Steve Ownby · 07-30-2012, 10:31 AM

Quote:

Originally Posted by GaryKD

Hi gramps66,
I don't usually notice what goes on under the hood. However, in the case of Navistar, I would not purchase a coach unless it was using the DEF fluid to meet pollution requirements. Navistar recently announced they will also use the DEF technology to comply with pollution requirements. Navistar engines currently on the road not using DEF may become "white elephants". Why take the chance?

This has been addressed by Navistar. The MF7 & MF10 are fully EPA compliant and will continue with their current systems. The engines they are having problems with and will add DEF to are the 13 and 15 which are Cat blocks with Navistar fuel systems. There are thousands of delivery trucks and school buses with the smaller Navistar systems. As EPA keeps making the standards tougher and tougher don't expect any system to stay in place long.