Excessive steam coming out vent tube(Diesel truck)?

Matthew K

Matthew K

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Broke Engineer
Hello all,

I have a 1999 Ram 2500 with 243,000 miles. I've noticed especially lately that there's been a fair amount of steam coming from the vent tube. I know when these trucks are warming up that's normal as water is boiling off from when the truck cooled down last. To prove my point, on my latest trip I drove two hours without turning off the truck and when I stopped at a red light near the end, their was still a very noticeable amount blowing out, long after all the water should have boiled off.

Now I have been losing some coolant, but that may be a leak in the rad since this truck is almost 20 years old, but I also don't know where else this steam may be coming from. There's no tale-tails coming from the exhaust indicating a blown head gasket.

Also don't know if I'm loosing oil as the drain plug is dripping(gonna get that fixed tomorrow actually) so I can't say if I'm losing oil via the vent tube.

Any supporting info would be appreciated.

Also, @Ted DuPuis I believe you used to have a cummins, any experience with this?
 
Excessive is a relative term.... could just be blowby on an old engine with lots of miles on it that wouldn't be a huge surprise.
 
cowman said:
Excessive is a relative term.... could just be blowby on an old engine with lots of miles on it that wouldn't be a huge surprise.
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By excessive I mean a good sized cloud of steam coming from the front of the truck that is visible from inside when stopped at a redlight.
 
That doesn't sound right to me. Steam condensate out the exhaust on very cold day is normal, but rising out of the hood? Sounds like a coolant leak.

Check your oil. Make sure it isn't a milky white color from coolant getting in to the engine.
 
Sac Arrow said:
That doesn't sound right to me. Steam condensate out the exhaust on very cold day is normal, but rising out of the hood? Sounds like a coolant leak.

Check your oil. Make sure it isn't a milky white color from coolant getting in to the engine.
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I would think the same, but the oil isn't milky at all.
 
That sounds like a coolant leak to me. To check blow by, take off the oil filter cap with the truck idling.
 
Ted DuPuis said:
That sounds like a coolant leak to me. To check blow by, take off the oil filter cap with the truck idling.
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I know of oil filters that have what some may consider to be a cap. I would not take it off while the engine is running.
 
Ted DuPuis said:
That sounds like a coolant leak to me. To check blow by, take off the oil filter cap with the truck idling.
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Took off the filler cap, I can feel a small amount of air coming out. Doesn't seem super significant.
 
Might be blow by slipping past the rings. Or just crank case pressure, a result of the engine running. Check crank case vent to see if it is blocked.
 
Zeldman said:
Might be blow by slipping past the rings. Or just crank case pressure, a result of the engine running. Check crank case vent to see if it is blocked.
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Vent definitely isn't blocked. Like I said when engine is warm there's considerable steam coming from it.
 
FInd someone who can pressure test the cooling system. If there is coolant leaking slowly into the engine, maybe a head gasket leak, you might try Bar's Leaks. When I was racing my engine builder used to swear by that stuff. He said that adding the Bar's Leaks to the cooling system was specified as a routine part of Cosworth engine rebuild instructions. The type we used looked like black rabbit pellet soup. It came in a clear plastic bottle. Not sure what the current replacement might be.
 
airdale said:
FInd someone who can pressure test the cooling system. If there is coolant leaking slowly into the engine, maybe a head gasket leak, you might try Bar's Leaks. When I was racing my engine builder used to swear by that stuff. He said that adding the Bar's Leaks to the cooling system was specified as a routine part of Cosworth engine rebuild instructions. The type we used looked like black rabbit pellet soup. It came in a clear plastic bottle. Not sure what the current replacement might be.
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That would be the next step, as airdale said, to pressure check the cooling system, or check for exhaust gas in the coolant.

Bars Leaks works good at stopping small water flow, such as leaks and the small tubes that the coolant flows through to cool the coolant, essentially stopping the coolant from flowing through the radiator, which will cause overheating problems. Any decent radiator shop will charge you much more for having to clean that crap out of the radiator.

This checks for exhaust gas in the coolant. Might find it cheaper elsewhere.

https://www.amazon.com/UVIEW-560000-Combustion-Leak-Tester/dp/B000NPDL76
 
airdale said:
FInd someone who can pressure test the cooling system. If there is coolant leaking slowly into the engine, maybe a head gasket leak, you might try Bar's Leaks. When I was racing my engine builder used to swear by that stuff. He said that adding the Bar's Leaks to the cooling system was specified as a routine part of Cosworth engine rebuild instructions. The type we used looked like black rabbit pellet soup. It came in a clear plastic bottle. Not sure what the current replacement might be.
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In the world I come from (Jaguar V12s) we hate Bar's Leaks. That stuff contributed severely to overheating on an engine that already liked to overheat.
 
open up the hood and look while it's making steam! I'll bet one of the plastic radiator side tanks has a crack. My '97 Dodge CTD did that. Rad was relatively inexpensive to replace.

Your post says it's venting out the vent tube ... do you mean the crankcase vent tube on driver's side? Verified by looking closely that's where it's coming from?

Maybe post your question on www.dieselram.com - some good folks there.
 
Bars Leak: Just say no. It's a great way to cause major problems. Fix the real problem.

Get the coolant system pressure tested.

Any white/light smoke at start?
 
gkainz said:
open up the hood and look while it's making steam! I'll bet one of the plastic radiator side tanks has a crack. My '97 Dodge CTD did that. Rad was relatively inexpensive to replace.

Your post says it's venting out the vent tube ... do you mean the crankcase vent tube on driver's side? Verified by looking closely that's where it's coming from?

Maybe post your question on www.dieselram.com - some good folks there.
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When I say steam I mean it's coming out the crankcase vent tube. When I look under the truck with the engine running I see it coming out the tube.
denverpilot said:
Bars Leak: Just say no. It's a great way to cause major problems. Fix the real problem.

Get the coolant system pressure tested.

Any white/light smoke at start?
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No smoke at startup besides a small black puff of unburnt diesel.
 
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UPDATE: Coincidentally my transmission started leaking major-ally today. From the looks of it it's coming out of one of the cooling lines. Just had the truck towed to a diesel pickup shop not far from me. I am going to have them look at the transmission along with everything else and see if they can come up with any evidence about the cause of the steam coming from the crankcase and any other possible issues.
 
Sure sounds like head gasket, warped or cracked head to me. The taiilpipe thing isn't definitive, the leak could be into the oil gallery. Do a leakdown test and see if you have a bad cylinder.
Any bubbles or foam in the radiator coolant (not the expansion tank ) when running?
 
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Chip Sylverne said:
Sure sounds like head gasket, warped or cracked head to me. The taiilpipe thing isn't definitive, the leak could be into the oil gallery. Do a leakdown test and see if you have a bad cylinder.
Any bubbles or foam in the radiator coolant (not the expansion tank ) when running?
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If there's a bad cylinder I hope the diesel shop catches it, but I'd expect to notice abnormal noises or vibrations if there was. I'll make sure to bring it up nevertheless. I recently put new coolant in the cooling system(was already doing the steam thing before hand) and didn't notice any foam/bubbles when I was done bleeding the system.
 
Matthew K said:
If there's a bad cylinder I hope the diesel shop catches it, but I'd expect to notice abnormal noises or vibrations if there was. I'll make sure to bring it up nevertheless. I recently put new coolant in the cooling system(was already doing the steam thing before hand) and didn't notice any foam/bubbles when I was done bleeding the system.
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I towed a 12,500 lb trailer over 1500 miles with a blown head gasket with a 5.9 Cummins. I thought it was a water pump leak, since it was external. Kept pouring coolant mix in. There was no indication of any other problem other than a slight reduction in power. On the flatland route I was pulling, it was barely noticeable. Just more throttle needed on hills. That engine is a tank.

Yours sounds internal. If the coolant level can't be figured out because there's another leak, that makes diagnosing it without a pressure test and fixing the other leak, tough. AFAIK that engine has no per-cylinder sensors to know if it's not producing power on one cylinder or reduced power.
 
Matthew K said:
If there's a bad cylinder I hope the diesel shop catches it, but I'd expect to notice abnormal noises or vibrations if there was. I'll make sure to bring it up nevertheless. I recently put new coolant in the cooling system(was already doing the steam thing before hand) and didn't notice any foam/bubbles when I was done bleeding the system.
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Wait, your not driving one of these, are you..??

 
Matthew K said:
If there's a bad cylinder I hope the diesel shop catches it, but I'd expect to notice abnormal noises or vibrations if there was. I'll make sure to bring it up nevertheless. I recently put new coolant in the cooling system(was already doing the steam thing before hand) and didn't notice any foam/bubbles when I was done bleeding the system.
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Any news?
 
denverpilot said:
Any news?
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Unfortunately for me, no. The guy I had the truck towed to is understaffed for the amount of work he has. I visited his shop today and he promised me that he'll have checked it from top to bottom by Monday afternoon, and assuming nothing hugely time intensive needs to be done, the truck fixed by Friday. Yay for me, I get to keep sharing a car :(.
 
Matthew K said:
Unfortunately for me, no. The guy I had the truck towed to is understaffed for the amount of work he has. I visited his shop today and he promised me that he'll have checked it from top to bottom by Monday afternoon, and assuming nothing hugely time intensive needs to be done, the truck fixed by Friday. Yay for me, I get to keep sharing a car :(.
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Hope you hear some good news on Tuesday.
 
Matthew K said:
Unfortunately for me, no. The guy I had the truck towed to is understaffed for the amount of work he has. I visited his shop today and he promised me that he'll have checked it from top to bottom by Monday afternoon, and assuming nothing hugely time intensive needs to be done, the truck fixed by Friday. Yay for me, I get to keep sharing a car :(.
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Unfortunately this is becoming the new normal. Seems like all the garage owners I know have the same problem. They can't get reliable help, or qualified help. One guy I know here in town is closing his shop and selling the property because of this problem. The business is there but the wait time is almost 30 days.
 
Zeldman said:
Unfortunately this is becoming the new normal. Seems like all the garage owners I know have the same problem. They can't get reliable help, or qualified help. One guy I know here in town is closing his shop and selling the property because of this problem. The business is there but the wait time is almost 30 days.
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Wow yea, this guy said he's been looking for good workers for the past 3 years. ATM he is just himself and one helper but could definitely use many more. He has I believe 6 or 8 bays for trucks to be parked in. It seems like landscaping businesses around here also have the same problem finding good work. Of course both of these could be considerably due to how much they're willing to pay the worker.
denverpilot said:
Hope you hear some good news on Tuesday.
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Thanks.
 
Update: Well the tranny lines are fixed, he showed me the old lines and there was a sizeable gash in them from a point they were rubbing each other. The new ones are routed differently so that there is no chance of rubbing. Also, I'm having the water pump replaced while it is there as I believe it is original and appears to be leaking(so maybe this is the source of steam, suppose I'll find out soon enough). The fuel filter housing is leaking, something I already knew of, but they're saying it has to be replaced and isn't fixable...I may start another thread on this. Also going to have the right rear main seal replaced, and change the diff fluid while it is there.
 
Matthew K said:
Update: Well the tranny lines are fixed, he showed me the old lines and there was a sizeable gash in them from a point they were rubbing each other. The new ones are routed differently so that there is no chance of rubbing. Also, I'm having the water pump replaced while it is there as I believe it is original and appears to be leaking(so maybe this is the source of steam, suppose I'll find out soon enough). The fuel filter housing is leaking, something I already knew of, but they're saying it has to be replaced and isn't fixable...I may start another thread on this. Also going to have the right rear main seal replaced, and change the diff fluid while it is there.
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Trans lines: Sounds like a mini-disaster avoided.

Water pump: Weird. What do they mean by "seems to be leaking"? A pressure test of the coolant system should show whether that's true or not, unless you really do have a head gasket leak that's big enough to not show leaks at the pump. And that would be a massive leak and it'd show up on the test as a leak and you'd not see coolant coming out anywhere. I believe they can also do a coolant dye test if they're being thorough. I personally don't like that phrase, "seems to be"... is that just a phrase you're using or is it what they said? Because my engineering-brained and smart-azzed answer to them would have been, "What test was used or is there visible coolant leaks and you can just see it?" and it wouldn't come out as mean, but I'm never happy with folks who guess. ("Are you a thinkin' man, or are you a knowin' man? You THINK I need a water pump... why do you think that?")

Fuel filter housing: Yeah, those crack and they're not usually repairable. Often from some donkey cranking on that end cap's "nut" shaped end where you can put a large socket on it to assist removing it to change the filter. They think it needs to be torqued down and just crank on the plastic cap until it breaks or the canister part cracks. Dumb. It doesn't need to be THAT tight.

Rear main seal: Ugh. Leaks. The bane of older vehicle owners and maintainers. But yeah, gotta fix 'em. Otherwise the vehicle marks its territory like an abused Harley. LOL.

Diff fluid: Not a bad idea. I have the Mag Hytec (sp) diff covers which add cooling fins/area and also have a magnetic dipstick. Makes checking the diff fluid level much easier and also you can see if the magnet has picked up any stuff as an early indicator something is wearing in the diff. If they're going to have yours off, might be worth a peek to see how much they cost these days. Mike have been on the truck for many years before I owned it.
 
denverpilot said:
Trans lines: Sounds like a mini-disaster avoided.

Water pump: Weird. What do they mean by "seems to be leaking"? A pressure test of the coolant system should show whether that's true or not, unless you really do have a head gasket leak that's big enough to not show leaks at the pump. And that would be a massive leak and it'd show up on the test as a leak and you'd not see coolant coming out anywhere. I believe they can also do a coolant dye test if they're being thorough. I personally don't like that phrase, "seems to be"... is that just a phrase you're using or is it what they said? Because my engineering-brained and smart-azzed answer to them would have been, "What test was used or is there visible coolant leaks and you can just see it?" and it wouldn't come out as mean, but I'm never happy with folks who guess. ("Are you a thinkin' man, or are you a knowin' man? You THINK I need a water pump... why do you think that?")

Fuel filter housing: Yeah, those crack and they're not usually repairable. Often from some donkey cranking on that end cap's "nut" shaped end where you can put a large socket on it to assist removing it to change the filter. They think it needs to be torqued down and just crank on the plastic cap until it breaks or the canister part cracks. Dumb. It doesn't need to be THAT tight.

Rear main seal: Ugh. Leaks. The bane of older vehicle owners and maintainers. But yeah, gotta fix 'em. Otherwise the vehicle marks its territory like an abused Harley. LOL.

Diff fluid: Not a bad idea. I have the Mag Hytec (sp) diff covers which add cooling fins/area and also have a magnetic dipstick. Makes checking the diff fluid level much easier and also you can see if the magnet has picked up any stuff as an early indicator something is wearing in the diff. If they're going to have yours off, might be worth a peek to see how much they cost these days. Mike have been on the truck for many years before I owned it.
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Water Pump: That was just my phrase to use :D. They showed me where it was leaking while I was there.

Fuel Filter Housing: Well this one isn't cracked as far as I can tell, it's leaking from the seal that the electrical wires go to on the top. I've read some forums on fixing it, but I think I'd rather install a new one, and it doesn't appear to difficult at all to replace so I may just do it myself.

Also, unless I've gone crazy, I filled up my truck with diesel 2 days before it was taken to the shop, and reset my trip meter, putting about 10 miles on it before it was towed. I picked it up today, with the trip mileage at 18, but at a half tank of fuel(which is less than half because the first half definitely takes more fuel)! I asked them about this and all they had to say was they drove to town and back to make sure everything worked, and that the fuel housing was loosing a ton of fuel and that is their explanation. I know for a fact that it doesn't loose anywhere near that much fuel for 15+ gallons to be gone, but I don't have any proof of them doing anything malicious, so I'm just left to taking the fuel hit and rethinking everything making sure I did in fact have a fuel tank of fuel. Between the long waiting time to get any work done, interesting variations in how much they charge per hour, and this, I'm currently looking at other possible places to get what work is left done.

P.S. I picked it up today before all work was completed because I'm taking our camper to sell it tomorrow. It is in drive-able condition, just some relatively small things left.
 
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