# Car problem - broken hose - critical? repair options? **URL:** \ **Category:** Factual Questions\ **Created:** [March 24, 2006, 11:13pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796 "2006-03-24T23:13:38Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![Jake4](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jake4](https://boards.straightdope.com/u/Jake4)\ **Post date:** [March 24, 2006, 11:13pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/1 "2006-03-24T23:13:38Z")
Hello to all automobile-savvy dopers. The car in question is a ‘98 Dodge Grand Caravan 3.8L. I opened the hood today to check oil & fluids before a longish trip and found a broken hose. The hose, about 1/2" OD, 1/4" ID, runs from the top front right corner of the engine block/“oil area” to the left side of the air filter casing. It had previously been repaired in the middle with what looks like regular-ol’ black electrical tape. (If there is some special automotive black stretchy tape, please enlighten me.) The tape job has come undone. I’m guessing that this is simply an air inlet to the “oil area” (help me with that term), running through the air filter so that dust/dirt/etc. doesn’t get into the engine. Obviously not a good thing that it’s open to unfiltered air, but I’m hoping this isn’t critically bad either. The car’s possibly been running in this state of disrepair for a while, since I haven’t cracked the hood since the last oil change, and it’s almost due for one. My proposed course of action is this: 1. Ultra-short term: Re-tape hose. (Suggestions for tape?) 2. Short-term: Change oil/filter. 3. Longer-term than #2: Replace hose. (Available at auto-parts stores near me? What to ask for?) Any answers to my numerous car-noob questions or comments on my thinking/situation greatly appreciated. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 24, 2006, 11:22pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/2 "2006-03-24T23:22:08Z")
The purpose of that hose, IIRC, is to feed blow-by gasses from the oil system back into the engine as part of emissions controls. As you surmise, it’s not critical to the engine’s performace, but no unfiltered air is being drawn into it–the airflow is the opposite of what you assumes. You should be able to temporarily repair it with duct tape (great stuff–Red Greeen knows what he’s talking about!) until you can get it replaced. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [March 24, 2006, 11:22pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/3 "2006-03-24T23:22:15Z")
Sounds like a PCV hose, no biggie. I suspect that most decent autoparts stores have it. They are usally just pushed on - no clamps, should take all of 10 seconds to change, 20 if it’s your first time - really. I suggest you try to do it soon though as unfiltered air is entering the crankcase - that’s right the exact same air you breath every day is getting in to your engine. Tape is a emergency measure you use to drive to the nearest auto parts store. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 24, 2006, 11:24pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/4 "2006-03-24T23:24:01Z")
> [@kanicbird](#): > > Sounds like a PCV hose, no biggie. _That’s_ the term I was looking for! Yes, it’s just as I said above–PCV stands for Positive Crankcase Ventilation. ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [March 24, 2006, 11:25pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/5 "2006-03-24T23:25:47Z")
It sounds like a crankcase ventilation hose. It’s not critical, but it should be repaired. I suspect it goes from the air cleaner to a valve cover, or possibly to the PCV (positive crankcase ventilation) valve, which probably inserts into the valve cover. Its purpose is to let oil vapors from the engine be sucked in with the fresh air going through the air filter so they’ll be burned inside the cylinders, rather than simply wafting into the atmosphere. You should be able to retape it. First, I’d clean the outside of the hose with a solvent like brake parts cleaner - tape won’t stick well to oily surfaces. Duct tape would be the best choice. Usually electrical tape will work, but it comes undone more easily. The hose will almost certainly be available only from a dealer. You might find replacement hose (cut-to-length) at a parts store **IF** it has no preformed bends, and **IF** you can find a parts store that has **oil-resistant** hose in the right size in stock. Any hose that’s not oil resistant will soon deteriorate in that application. I don’t see a need to change the oil. Generally blow-by pressure is pushing vapor out, I doubt it’s sucking air in. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [March 24, 2006, 11:26pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/6 "2006-03-24T23:26:53Z")
> [@Q.E.D.](#): > > but no unfiltered air is being drawn into it–the airflow is the opposite of what you assumes. What happens when you shut off the car and the air inside the crankcase cools off? ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [March 24, 2006, 11:28pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/7 "2006-03-24T23:28:23Z")
Well, it is possible air is being sucked in through the hose. I’d have to know the layout of the PCV system on that particular engine to say for sure. Even so, I don’t think it requires an oil change for that reason alone - but I would fix the hose. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 24, 2006, 11:33pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/8 "2006-03-24T23:33:25Z")
> [@kanicbird](#): > > What happens when you shut off the car and the air inside the crankcase cools off? Very little, I should think. I can’t imagine the resultant contraction pulling in more than a couple pints of outside air. You’ll get more dust in your engine just by adding a quart of oil, I bet. If you’re uber-paranoid about it, you can always plug the end of the hose with something, such as a golf tee. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [March 24, 2006, 11:36pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/9 "2006-03-24T23:36:56Z")
> [@Q.E.D.](#): > > Very little, I should think. I can’t imagine the resultant contraction pulling in more than a couple pints of outside air. You’ll get more dust in your engine just by adding a quart of oil, Well don’t forget about water that can enter and condense on the inside of the block esp. while it’s sitting overnight. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [March 24, 2006, 11:39pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/10 "2006-03-24T23:39:07Z")
actually now that I think of it, air is going to enter anyway as the crankcase does not form a vacuum, though it is a pretty big opening. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 24, 2006, 11:38pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/11 "2006-03-24T23:38:53Z")
> [@Gary T](#): > > Well, it is possible air is being sucked in through the hose. Isn’t there usually a PCV valve on the valvetrain cover where the hose is connected, that would prevent air from flowing in the other way? I don’t know about this particular vehicle, but I recall having to change one on a '67 Camaro I once owned. I’m about 80% certain it was on the valvetrain cover, not on the air cleaner. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [March 24, 2006, 11:43pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/12 "2006-03-24T23:43:30Z")
> [@Q.E.D.](#): > > Isn’t there usually a PCV valve on the valvetrain cover where the hose is connected, Yes you are correct - so the engine is protected. It seems like the duct tape option is looking better. ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [March 25, 2006, 12:30am UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/13 "2006-03-25T00:30:05Z")
Okay, I’ve looked at the system diagram. The PCV valve goes into the intake manifold. One PCV hose connects the valve to the rear valve cover. This is where the engine vapors get sucked in to burn with incoming air. The other PCV hose - the one being discussed here - goes from the air cleaner to the front valve cover. This is where air comes in from outside (through the air filter) to allow the flow of vapor through the PCV valve. So this hose does suck air, assuming the PCV valve is not clogged. The flow path is air filter --\> front hose --\> front valve cover --\> through crankcase --\> rear valve cover --\> PCV valve --\> rear hose --\> intake manifold --\> cylinders. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [March 25, 2006, 12:45am UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/14 "2006-03-25T00:45:28Z")
> [@kanicbird](#): > > Well don’t forget about water that can enter and condense on the inside of the block esp. while it’s sitting overnight. So? As soon as the engine warms up the water vapor evaporates. ---
**Author:** ![A.R.Cane](https://avatars.discourse-cdn.com/v4/letter/a/ee7513/32.png) [@A.R.Cane](https://boards.straightdope.com/u/A.R.Cane)\ **Post date:** [March 25, 2006, 1:50am UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/15 "2006-03-25T01:50:07Z")
Allowing ambient air to enter the crankcase results in increased condensation, some of that water will get into the oil cause an acid buildup and affect the oils lubricating ability. This is the primary reason for more frequent oil changes in a vehicle that does many short trips vs. longer oil change intervals in a vehicle that is used, primarily, for highway driving. I’m going to take a WAG here, you probably haven’t had a tune-up lately. A competent shop will check for problems like this and advise you that they need attention. If this hose is deteriorated, it’s a fair bet that there are others that need attention. These things can effect engine performance, fuel mileage and can turn into expensive repairs if neglected long enough. I’d suggest you get a tune-up and specifically ask that they check things, like hoses and belts to see if they need replacement, and advise you. It’s money well spent in the long run. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [March 25, 2006, 3:43am UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/16 "2006-03-25T03:43:53Z")
While I agree that getting the car in question checked out is a good idea, go back and read **Gary T** ’s post #13. Ambient air is supposed to go into the crankcase, that what the hose in question does, it directs filtered air from the air cleaner to the valve cover. I can see no increase in condensation or acid build up from this hose being broken. There will be a slight increase in dirt entering the crankcase due to the air not being filtered. This is not good and should be corrected. ---
**Author:** ![A.R.Cane](https://avatars.discourse-cdn.com/v4/letter/a/ee7513/32.png) [@A.R.Cane](https://boards.straightdope.com/u/A.R.Cane)\ **Post date:** [March 25, 2006, 5:15am UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/17 "2006-03-25T05:15:36Z")
> [@Rick](#): > > While I agree that getting the car in question checked out is a good idea, go back and read **Gary T** ’s post #13. > Ambient air is supposed to go into the crankcase, that what the hose in question does, it directs filtered air from the air cleaner to the valve cover. I can see no increase in condensation or acid build up from this hose being broken. There will be a slight increase in dirt entering the crankcase due to the air not being filtered. This is not good and should be corrected. Good point. I wasn’t so much responding to the specific hose that was broken, as I was to the idea that condensation simply “evaporates”. Condensation does diminish the quality of the oil, it doesn’t just evaporate w/o doing any harm, that’s my point, but of course the grit that is induced is also detrimental, as you point out. ---
**Author:** ![Jake4](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jake4](https://boards.straightdope.com/u/Jake4)\ **Post date:** [March 25, 2006, 1:45pm UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/18 "2006-03-25T13:45:19Z")
Thanks for all the replies. I did a quick re-tape with electrical tape. I had considered duct tape, but nixed that idea since duct tape tends to melt (they don’t even use duct tape on hot ducts because it melts, for cripes sake) and the hose is pretty close to the engine block. GaryT, thanks for the advice on looking for oil-resistant hose. Obvious, perhaps, but not something of which I would have thought. On the subject of condensation/oil change, like I said, it’s due for a change anyway, so in my case the question is moot. On the matter of ‘getting the car checked out’, I’m approaching 150k mi. I received this car at about 117k and had a dealer do the 120k mi service. What work should I expect to be done at the 150k mi service? Also, what’s a new serpentine belt tensioner run for this vehicle? How much time for labor? Thanks again, guys… ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [March 26, 2006, 2:59am UTC](https://boards.straightdope.com/t/car-problem-broken-hose-critical-repair-options/349796/19 "2006-03-26T02:59:06Z")
> [@Jake4](#): > > What work should I expect to be done at the 150k mi service? Could be all, most, or some of what was due at 120K. If you have the owner’s manual with maintenance schedule, that will list the factory recommendations. Most dealerships and some independent shops produce their own maintenance lists, typically based on but not identical to the factory list. Typical service items include: Replace spark plugs. Replace air filter. Change engine oil and filter. Rotate tires. Flush and fill engine coolant. Service automatic transmission (fluid and filter change, or fluid flush and fill). Inspect many items - hoses, belts, brakes, steering, suspension, exhaust, etc.