Coolant leak

[suminfinit92]

I've just finished reading a thread on a 94 Q that sounds alike the problem that I'm having. For about two weeks I've smell antifreeze or an odor like the engine is overheating. The temp gauge was staying in the normal range and I've never seen any fluids leaking from under the car. Today, four days before our vacation, we were leaving the supermarket, when the temp gauge went to the hot range. I arrived home and checked under the hood, all the leaking antifreeze is sitting in the valley between the two heads. Where do I begin? Will the upper intake manifold have to be removed? ect. ect. ect. You guys have help me a great deal in the past and any info will be greatly appreciated. Thanks in advance. :help :help :help

[911/Q45]

Do a search on under plenum hoses.

[suminfinit92]

Sorry but I'm working blind, where are the plenum hoses? Would I have to remove anything?

[911/Q45]

The under plenum hoses are under the plenum, what you called the upper intake. After 12 years all the underhood rubber is cooked. You are looking at about $600 in parts from Scottsdale Infiniti, which has the best prices. If you aren't a do it yourself guy, labor to replace the rubber is about $1000. Search this site for detailed info.

[elwesso]

Check out http://www.Q45.org and check out my PLENUM WRITEUP...

[maxnix]

And if you have antifreeze everywhere, be sure to have the knock sensors and harness at the ready. Testing procedure has been posted many times before, but if they are old or cracked, you will want to replace them anyway to preclude having to pull the plenum soon again when they fail.

[suminfinit92]

Man, it looks as if I have my work cut out for me. I'm going to take this on this weekend. Thanks for the great info. You guys are the best. Thanks again.

[Highway Q45]

Be ready to swear a lot but take your time. It's also a good time to flush the plenum, throttle body, clean the IAC and EGR. Try to have some replacement hi-temp wire sheath on hand, those sensor wires will be very brittle and benefit from external protection. Good luck and have bandages ready! At least Joe has a ready made package now...those of us that did this over a year ago were kind of flying blind at first.

[squeefoo]

I bet the crossover hoses are loose - mine were. I put the clamps on so I can periodically tighten them through the plenum runners, with extensions (and patience). Might as well change what you can -you'll find out why. I made that mistake and I've had it off 4X.But I'm real good now!

[suminfinit92]

Just can't wait to get started, yeah right. Once again, thanks for the advice.

[pito11213]

If you are questioning whether to go with joe or not here is something to sway your decision.

I had the similar coolant smell and finally the temp needle went up when i put on the ac.

Well I got my guy to pull the plenum(by the way congrats to anyone who has done it as it looks like hell.) It turns out that one of the hoses on the y-pipe had a cut underneath, I believe it was because of the rise of temp causing the hose to burst.

Well I decided due to time conflicts that I would take the hoses that were broken or lost their flexibility to the dealer and have them replaced. Oh lord.

I bought1. thermostat2. pcv valve3. plenum gaskets for the runners4. 5 hoses, each no longer than 5"5. Both hoses for the y-pipe6. can of BG 203 - they didnt have the recommended 44k but said this would work just as well.

Just the 5 hoses came to $140!!!!!Total I spent about $220 dollars on the above parts.My guy did only charge me for $220 labor and I stand by his work.

Take my advice and buy the entire kit from Joe for about $220 that include all air and coolant hoses.

[elwesso]

..... Except that Joe's kit doesnt include EVERYTHING you need.....

[maxnix]

Very true, it is really a minimal starter kit. Every hose includes more than are in the kit.

[Q45tech]

Depending on where you live [ambient heat] and your driving/parking style, the hoses start to leak anywhere from every 80,000 miles to 130,000 miles.

Should just be mandantory to change EVERY hose in engine compartment every 100,000 miles..........including AC, fuel, PS. vacuum, air, coolant, heater etc.......roughly $900 in retail parts.

Then you can drive worry free for the next 100,000 miles.

One LONG visit to shop instead of a half dozen as leaks progressively develop.

The knock sensors almost always fail before 200,000 miles [10 years] on 90-01 Q..............whether you preventitively change them and their harness [$400 in parts] while the plenum is off depends on taking the long view to costs..................and whether you live in a state that eats fuel injectors due to special fuel blends.

Always change the spark plugs when you do valve cover reseals as the increment is tiny.

[suminfinit92]

Thanks, I let you guys know what happens.

[suminfinit92]

Does anyone have Joes' phone number?

[maxnix]

It on the left and on the site http://www.everythinginfiniti.com .

It's on my speed dial so I don't remember it.

[elwesso]

I have it memorized!!

1888-216-5328

[suminfinit92]

Thanks.

[suminfinit92]

Well, I've replaced all the hoses under the plenum, and I'm ready to reassemble. Is there a torque sequence for the plenum. Thanks again for the advice.

[Q451990]

I don't remember one, but I always tighten them all finger tight, then cross from one corner to the other with a half torque, and then repeat with a full torque. The plenum to runner bolts are very soft, so you don't want to overdo it!

Heath

[suminfinit92]

Thanks for the info. I'm looking forwards to finishing this job.

[maxnix]

Keep going with patience and care. Don't want to forget to connect a hose! Do clean the inside of the plenum while it is off.

[elwesso]

DEFINITELY... The added smoothness and what you pull out of there will amaze you.....

Make sure you take all the hoses off, and go to town with some paint/varnish remover..... no paint on the plenum so it wont hurt it...

[suminfinit92]

Finally done, the cars runs great. As much as a pain it was to repair it, I'm glad I had done it. Thanks for all the help guys.

[Q451990]

Yeah - another plenum job on NICO! Now it's time to enjoy driving with your scarred, bleeding hands They'll heal in no time.

Heath

[suminfinit92]

Your right about that.

[911/Q45]

Well done!

[GuidoInc]

My left hand got beat up by trying to reconnect the IAC. I got those mechanics gloves but I couldn't not feel the opening of the bolts to use them.

[suminfinit92]

I hadn't removed the knocker sensors so when a bolt dropped into the valley I had to fish it out, after I scratched up my had a couple times I went a got one of those extendable magnets, I had read Wes's link on removing the plenum and I can't stress the importance of covering the intake manifold ports. Here's a helpful tool, digital camera take pictures of where the hoses locations are and if you get stuck on reassembly you can refer to the pictures later on.