Under Plenum Coolant / Antifreeze Leak

[lino]

My car has a coolant leak coming from under the plenum. I can see the puddle behind the waterpump. (My radiator, waterpump, thermostat, thermostat housing cap, and radiator cap have been replaced.) I was wondering if there may be some way to change the 1 hose that is leaking temporarily without having the remove the plenum since I'm not financially ready for a full plenum job right now. It appears to be the hose that is circled in red in the pic below. It seems to be leaking right wear the clamp is. It could be the one circled in blue too:

[cccpman]

sorry, there is absolutely no way to replace that with the plenum on. The real downside is that since this is probably your first under plenum job in a while you will lose an awful lot of hoses in the process of removing it

Furthermore when you replace the red hose you will basically HAVE to replace the blue hose (best bet is to cut the blue hose in half, or your going to spend a couple hours getting it out). If you need any help, Q45.org has the bible of under plenum work

Your just going to have to park the car until you get the funds to replace it (These are MAJOR hoses, your system will be dry in just a minute or two of running and overheat, possibly killing the car forever), if you DIY its 10-30x cheaper then letting an infiniti mechanic do it probably. Ask for help if you need it, a lot of us have done some work under the plenum and a few of us now have every torque value, every part, memorized

[Q451990]

Ditto... that hose is difficult enough to replace with the plenum off. Took me several hours of messing with it. Absolutely impossible w/o removing the plenum

Heath

[lino]

[yodawill2000]

Dang Bud .Sorry to hear bout' that.

[Jesda]

Lino... you never get a break from this car! LOL.

I took some shortcuts, since my hoses were in good shape, and just sort of moved the plenum out of the way without disconnecting absolutely everything. Saved a lot of time and energy and gave full access to everything underneath. Watch out for that pesky hose in the back.

[lino]

Thanks guys for the support.

Lino... you never get a break from this car! LOL.

My Q needs a suggah daddy...the dirty bit*h. After all the love I invested into this relationship.

[T45]

That hose is the one that was bad on my Q donor when I bought it. Apparently they traded it in when they found out how much it would cost to fix the hoses and an injector. lol I just took the old one to Advance and the guy let me in the back to find hoses that worked for me. I spent 60 bucks but was able to make all of the under plenum hoses up. The only one I had to go back for was a PCV hose that made a U turn and the heater hose I got wouldn't do it without kinking. If you spend some time making them you can do the whole job cheaply.

[mxr662]

Is the hose split or is it leaking around the clamp? On my 1990, one of the hoses had the spring type clamps like in the picture. The leaking hose had the wire clamps with screws. I had to replace injectors, but my clamps probably could have been tightened to stop the leak. This is the picture of my new hoses. I reused the spring type clamps because they were the ones that were not leaking.

[lino]

One of my hoses has the clamps with screws and the other has the spring type clamps. The leak is coming from the the one that has the screws and I can't tell for sure if it is split or just leaking. It seems like there's a split right at inner clamp and I can't see the screw to try to tighten it.
Modified by lino at 5:05 PM 9/19/2007

[cccpman]

well I recommend you save up until you can afford the under plenum job and have a day off

Both the spring and that particular screw clamp are EXCELLENT, dont replace either depending on what you have. If you go out and buy a new one, its going to have a screw on one side (but teeth along the entire clamp, you will know what im talking about because its all they normally sell), those WILL be the problem and cause leaks (been there). As for those two hoses, go OEM, I dont know why but fitting others has been a pain for me, also really hard to find one that will fit snug

That little Y shaped set of hoses and aluminum is possibly the worst part of engine work (in frustration). But a tube of RTV and use most of it, better safe then redoing the job

I would personally remove the lower intake manifolds too, its only a couple bucks to pay for the gaskets to re-seal them (you can clean them, they need it badly) and it really gives you a lot of room for that Y shape of death to work in easily to a 5 minute job, probably works out to be the same amount of time total either way. Plus you get to take a look at your fuel injectors - and clean them if you really wanted

ANY questions at all feel free to ask

[3Q Jay]

90-92 (93?) use spring clamps on the crossover hose, 94+ use the 't-bar'.i agree with cccpman, the t-bar clamps are oft maligned and discarded with impunity by the gas station grease monkeys. but they really are a superior product. you don't need to overtighten them on new rubber, i've never had one leak.

[sdkhalsa]

My car has a coolant leak coming from under the plenum. I can see the puddle behind the waterpump. (My radiator, waterpump, thermostat, thermostat housing cap, and radiator cap have been replaced.) I was wondering if there may be some way to change the 1 hose that is leaking temporarily without having the remove the plenum since I'm not financially ready for a full plenum job right now. It appears to be the hose that is circled in red in the pic below. It seems to be leaking right wear the clamp is. It could be the one circled in blue too:

One place that you might check, which was a problem with my 94' Q, is the thermostat housing gasket. I had a small leak at the bottom of this gasket which oddly enough caused a puddle of coolent under the large hose circled in red on your drawing. In other words, are you shure that this hose is defective. There are many places to spring a leak in the system that are not obvious. It is probably worth it to use leak detector to verify.