| Author |
Message |
Terry (66.82.9.34)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, May 01, 2003 - 9:41 pm: | |
My MCI 8 with 8V71 and Allison 4 speed auto belches out a cloud of blue smoke on start up that lasts maybe 5 to 10 seconds then stops. Climbing a steep hill when it starts to work hard it will put out some black smoke. Same black smoke when I started out today from a roadside rest area and had to hit the interstate on an uphill climb until I got it up to speed. Anything to worry about, or is this acceptable. |
Tom Caffrey (Pvcces) (64.114.233.254)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, May 01, 2003 - 10:31 pm: | |
Terry, it depends. You don't say the miles on the engine, whether it's a new symptom, which injectors you have or what elevation you were at.
If you have 65 or larger injectors OR if you're at a mile of elevation, the black smoke is probably to be expected. If you're at sea level and you've got C60 injectors, standard timed, then I would be concerned.
We are running C60s in a standard timed 8V71, with low miles, and we don't see any smoke until we get above 4,000 feet. At that elevation, atmospheric pressure is down to something like 13 psia, a drop from sea level approaching 15%.
The main reason for black smoke is loss of air into the engine. The main reason for blue smoke is probably burning of lube oil, although fuel accumulation in the exhaust system from idling can add to lube oil to make a pretty good cloud.
If you have a misfiring cylinder or a water leak while at high elevation pulling hard, you can wind up with a grey cloud (mixture of white and black smoke).
I hope you were just at high elevation or have the big injectors.
Tom Caffrey PD4106-2576
Suncatcher |
Terry (66.82.9.19)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, May 01, 2003 - 10:37 pm: | |
I was coming through the mountains in New Mexico and Colorado. Not sure what injectors I have, the engine has a lot of miles but runs real strong. I've never had it in the mountains before, and it does not do it at lower altitudes. The blue smoke on startup has always been there, more so in cold weather |
Buswarrior (Buswarrior) (64.229.209.223)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 02, 2003 - 12:28 am: | |
Terry,
Many here will be envious that your blue smoke goes away that quickly!
Seriously, the puff of blue on start-up sounds fine. The engine just pulls a little lube oil past the cold parts, or it has seeped down into a cylinder after shut down. No worries, unless it won't go away!
Also, the altitude conditions appear to be the determining factor in your case, since it has appeared up in the mountains.
Another popular and easily fixed problem will be if the air cleaner is beginning to be plugged, it will blow black smoke. Having one of those vacuum indicators for the air cleaner is a great little add on for an older coach. Takes out the guess work.
happy coaching!
buswarrior |
Peter Broadribb (Madbrit) (65.73.176.40)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 02, 2003 - 2:29 am: | |
Oh, those wonderful little vacuum indicators, now I wonder where have seen some for sale......
Ah yes, I remember now....... It was in the Flea Market on BNO.
I wonder who is selling them....... My goodness, it's me....... LOL.
Peter. |
John Rigby (63.185.81.79)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 02, 2003 - 3:24 pm: | |
Peter
Do you have them for an 4104/671? where do they go? Are they easy to mount? How much are they?
tHANKS
John |
Peter Broadribb (Madbrit) (216.67.210.17)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 03, 2003 - 6:54 am: | |
Just to let everyone know, all the sensors have been spoken for.
Thanks for your interest.
Peter. |
John Rigby (24.174.235.126)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 03, 2003 - 7:39 am: | |
Does anyone else know of a good sensor? Has anyone else had any experience with them? where did you buy yous?
Thanks
John |
John Feld (204.184.224.11)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 05, 2003 - 5:58 pm: | |
John,
I will have 8 of the new filter minders for sale coming in the next week or so (I bought 10 at a good price). E-mail me for info:
heritagehub at lycos dot com
Same price, 10.00 + S&H , anyone else need one? |