67_Rmodel_sta237 Posted February 18, 2013 Share Posted February 18, 2013 Just wondering if it can be fixed or at least made to be not as bad..Our 67' Open Cab R model just pukes whitish gray exhaust, the smell is bad and will damn near burn your eyes out...I pulled it on to our apron at our fire hall just to run it for a bit while I swept up a bit and the exhaust starts off gray then after awhile white. It's just constant never stops bellowing out...Any help, advice, and knowledge would be appreciated! 1 Quote Link to comment Share on other sites More sharing options...
staxx Posted February 18, 2013 Share Posted February 18, 2013 Is it a sweet smell , that would be coolant , if it is burning your eyes thats unburnt fuel . Is the engine running smooth or a slight miss ? Could be a stuck or cracked injector nozzel . If it a nozzel you can do a cylinder cut out by cracking open the fuel lines at injection pump one at a time one at a time when smoke goes away thats the cylinder that has issues. Quote Link to comment Share on other sites More sharing options...
67_Rmodel_sta237 Posted February 18, 2013 Author Share Posted February 18, 2013 It's far from sweet that's for sure, as far as running its smooth. Hell last I looked we've only got about 35,000 miles on it.But I'm sure time has taken toll on this beast, but I'm just trying also to save time and money in repairs that can be done in house so to speak.Any additives or such that could help? Quote Link to comment Share on other sites More sharing options...
Lmackattack Posted February 18, 2013 Share Posted February 18, 2013 I know the smell.. It's half burnt fuel. does it do this when engine temp is warm? Or Just after start up? Quote Link to comment Share on other sites More sharing options...
farmer52 Posted February 18, 2013 Share Posted February 18, 2013 Burning sensation usually is an indicator of unburnt fuel. Could be low compression or per Staxx, a bad injector. Does the smoke go away after it is at operating temperature and driven? Quote Ken PRR Country and Charter member of the "Mack Pack" Link to comment Share on other sites More sharing options...
fifth wheel Posted February 18, 2013 Share Posted February 18, 2013 Valves might be to tight, does it fire off right away?FW Quote Link to comment Share on other sites More sharing options...
67_Rmodel_sta237 Posted February 18, 2013 Author Share Posted February 18, 2013 It's starts up good, runs like I would hope it should but the exhaust is a constant thing from start up till you turn it off. Quote Link to comment Share on other sites More sharing options...
220cummins Posted February 18, 2013 Share Posted February 18, 2013 They all (older macks) will smoke at start up especially in colder weather. But if its still smoking and blowing out raw fuel at operating temp. then you have an issue like some people suggested. Check your injectors and if you need them serviced or pump work call R.A. Watt Fuel Injection (Watt's Fuel Injection) in Bradenville,Pa He'll help you out. He's a good guy. We've been using him for years now. Quote Link to comment Share on other sites More sharing options...
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