deanrd

Well I thought I was out of the woods, but here I am on my way to Florida and the hest light comes on after 50 miles, on for 20, then off again for about 50. Repeat repeat. Everything running ok. All gauges normal. Just gonna drive. Will find another garage when I get back or trade.

Picked it up today and so far so good. They did find the problem area after pulling radiator. The wiring harness was routed behind the belt tensioner and idler pulley, but had enough room to move into the serpentine belt. This rubbed thru the protective sleeve and 4 wires were chafed thru. They repaired the wires and ended up replacing the idler pulley and serpentine belt that was ready to shred. They also made another clamp to restrain the harness to keep it from repeating. Thankfully they caught it now and not me out on the road. They actually ran a forced regen as the error messages I was getting had it thinking I still needed a regen, but not being driven fast enough to start. They told me I needed to let it complete a regen whenever it starts and I will when possible if I can. I read that if stopped before completing then it should restart after on its own. We will see. Thanks for all the responses! Dean

Well it's back in the same shop. They said they found a short in harness. Waiting to see what happens. Hopefully by the end of the week I'll know more and so will you. Dean

When I asked about 7th injector I was told there isn't any and it's done by the ECM. Not sure what it does different. Temp gauge only goes from stone cold to boiling hot and back again, happens within a minute of cold start. Tranny temp is constantly good. Curious about driving habits. I was told full throttle was just dumping too much fuel it couldnt burn so I'm a lightfoot trying for economy (haha) driving. When you say disconnect chassis are you referring to the battery disconnect? Up until this last event the HEST light came on when driving about 62mph for 15-20 minutes. Last time was 35-45mph after driving 3 miles from cold start.

Thanx for all the suggestions. I'm making notes as my tech wants one more chance. I forgot a few things. 12/21 I had to replace turbo speed sensor. For clarification, this model doesn't use def fluid and the last time they worked on it they did a forced Regen. Also the temp gauge acts up within 5 minutes of cold start and it's not a slow rise to hot, it pegs out, then drops to stone cold. I will take this list in for Fridays appt and see where we go. Thanx again Dean

Hi All, This is the saga of my DPF HEST light. I originally posted this on IRV2 and was referred over here for more help. I have a 2008 HR Ambassador 40SKQ with 360 Cummins. Occasionally, up until now my regeneration cycle would run maybe once every 750 miles or so. I went to Florida the end of March and it came on maybe two or three times, so slightly more than normal. Coming home however it would come on 2 or 3 times a day. Should I be concerned? Is this an indication of looming problems? No other indications. It runs maybe 15 mins or so and done. I'll include pic of light. It's indicator 5, HEST High exhaust sys temperature. Says regen in process. These don’t match my owners manual, but match my dash 😞 I was asked about idle time and that is kept to a minimum. My DPF has supposedly been checked and is clear. One reply: Another cause of high exhaust temps can be a leak in the pressure side of your turbo, as in your charge air cooler or the boots connecting the pipes. These were also checked as SAT. Flash updates are supposed to be SAT also. Well so far they had me replace fuel and air filters. They've scanned and no codes or any recorded. Took it to Vermont. Roughly 130 miles each way. Came on within 20 miles each way, once again about halfway and again towards end. Hopefully they can find something. Well they said my vgt was only opening 22 degs. Replaced it, not cheap. Drove 15 miles yesterday and HEST light again. Back in Monday, grrr DPF has not been cleaned, performance seems normal. Actually slightly better with VGT replaced. Always Ultra low sulphar fuel as far as I know. I’ve even started adding Diesel Kleen. Lastly… OK, time to find a new repair shop. After leaving it for over a month nothing has changed.. Even after replacing VGT the problem persists. Now my engine temp gauge will stay on cold and then suddenly will peg at hot, then warning light comes on. Ten seconds later the temp gauge drops back to zero. After being told everything was working I drove 5 miles to get the HEST light came on for a minute, then off about 1 min., then back for a min, then off, but Regen required light came on then started flashing. I think my DPF needs cleaning in spite of what they said. So frustrated... Still flashing regen required light, regen HEST light on and warning light. Engine temp gauge still fluctuating hot to cold even at cold start. Waiting for return call for service, but looking for new technician. I think it’s my dpf clogged, but they say they’ve tested pressures, so… Thanx Dean