harpelt

I searched for this question, so sorry if it was already asked before. When I start up my 68 Cutlass Holiday Coupe (350) I am getting a lot of rusty water coming out of the tail pipes. I have aftermarket headers and dual exhaust on this car (the product of my late 20's and gearhead friends) The car needs transmission work so I don't drive it at this point, i just make sure I start it up every weekend and run it for a few minutes to get the engine warm. I also have an aluminum intake manifold and 4 bbl carb on this car with an electric choke. It starts up quickly as long as I start it each week. The car is garaged, by the way.

I am wondering if the 20 year old steel exhaust pipes and relatively cheap mufflers are holding moisture and that's what I am seeing or if it might be something worse. Any advice on what to check would be appreciated.

jmos4

Hi,

If you're only idling the engine, its most likely not blowing out the moisture and or heating up the exhaust system enough to cause the moisture to evaporate.

Also a lot of mufflers don't have drain holes or not oriented to let water out.

I run my cars in winter storage for about a half hour and rev them up a few times to help with that.

Regards,

Tedd Thompson

My guess is yes. Though you start it weekly it's doubtful that the exhaust gets warm/hot enough throughout the system to dry everything out, then when it does cools down you get condensation again and the moisture thing starts all over again and so does the rust...... Tedd

bccan

IMO if car isn’t being driven don’t start it if you’re not going to get engine up to full temp. Running it for a few minutes only creates condensation that never gets blown out or evaporated as it would when driven or at least brought up to temp for a period of time.

harpelt

Thanks for the quick answers! I will start running the engine for a bit longer to see if I can get it to dry out more.

Sugar Bear

If you are going to run it, get it to full temp for 5-10 minutes and then hold it at about 1500-2000 for a minute to dry the exhaust. As stated then it starts over, hot exhaust... condensation...

PatL

you really need to drive it instead of short idles, otherwise it is best just to let it sit; put stabilizer in the fuel and disconnect the battery.

BillK

Absolutely the worst possible thing to do. Just let it sit until you get the trans fixed. Like others have said you simply cannot get everything hot enough to get all of the condensation out without driving the car. Sitting wont hurt a thing.

oldcutlass

This why exhaust pipes and mufflers rot from the inside out, short trips that do not allow all the moisture to evaporate from the system. You will not get the exhaust system warm enough to do this by idling. Like the others stated above, if your not going to drive it, don't start it.

Vintage Chief

I'll second what Eric stated. I have owned motorcycles almost my entire life (those w/ a carburetor and EFI). On another forum I have been a member 15+ years one of the common threads is related to not rusty water from the exhaust, but premature failure of points, ignition coils, BCM, etc. and these nearly always occur with folks who insist on maintaining the life of the battery by starting their motorcycle once per week or so. Nothing could be more damaging. If you want to maintain the battery, take it out and set it on the bench. This is closely likened to numerous quick trips of 15' or less. Enough to create condensation, but not enough to burn it off and generally not nearly long enough for the stator to supply enough voltage to the VR to recharge the battery to begin with.

Cutlass Fan

x2, starting an engine and letting it idle until you think it is warmed up is probably the worst thing you can do to an engine! Unless you can drive it long enough to warm the oil enough to evaporate any condensation don't start it.