2004 Acura MDX idle issue when cold.?

Well Al if you've not yet checked/cleaned/set the spark gap/replaced the plugs I'd sure recommend that you start there.Don't forget the plug wires and be careful bec even though you may purchase new plugs and the packing/sales clerk indicates the plugs the spark gap is set by factory always check and double check the spark gap of every plug.

That also has a MAP sensor it may require cleaning and if you wish to learn how to check youtube and they do have different vids explaining how the MAP sensors work and how to clean them.Also it has a air charge temperature sensor that may require cleaning/replacing but again start with the basic tune up and see how it runs.

Hope that helps and best of luck.By the way it doesn't hurt to have the battery/charging system and starter checked especially the battery.Most part stores will perform these tests on the spot for free without you having to remove any of the parts.

Why is it that every mechanic says "you needed new plugs and wires and a new battery and new cables... here's the bill" like helpful Bob did? That almost never works. If the engine runs smoothly warm, it's probably not an electrical short in the plug wiring.

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The acura MDX is has a drive by wire thottle system. An electronic throttle and gas pedal.. not a cable! The RPM is automatically measured and adjusted by the PCM (powertrain control module.. the onboard computer). There are number of things that can go wrong with the idle adjustment system... including carbon buildup in the throttle body and even.... strange as it may seem.. poorly adjusted valves clearances.

IF the check engine light is NOT on, according to the service manual, 11.225 step 5 goto step 15. Step 15 reads "remove air intake from throttle body. Step 16 "check for dirt, carbon and damage to throttle body". etc. Good luck with that solution. It maybe worth your while to take the car to a shop and have them diagnose the problem because it could be one of several different things.

My own personal experience with the exact same problem is this. I took my car to a shop and they performed routine maintenance which included a valve adjustment at 75,000 miles. Immediately after that, the gas mileage dropped 5mpg, the car ran rough cold but better warm. Within 6 months, the check engine light started to come on occasionally with "random cylinder misfire" codes.

I took my car back to the acura dealer where I had the maintenance done and when I complained, they said "it's an older car. It has a lot of miles. Don't expect the same performance" etc and they recommended a $1500 throttle body replacement. So I took it to another shop who immediately recommended a valve adjustment job for $875 (which had just been done). And another shop who recommended exploratory surgery. And another that recommended "new plugs and wires!".

Being another weekend mechanic, I decided to double check the last work the mechanics did on my car. The valve adjustment. So I took off the intake manifold and valve covers and checked the adjustments. There are 12 intake and 12 exhaust valves on my car. Half of them were incorrectly adjusted. The back intakes were set to the exhaust clearance and the exhaust were actually partially open during the combustion step. The front intakes were set correctly... but the front exhausts were set to the intake specs. It's as if 1 mechanic started the work on my car and thought the intakes were the exhaust valves. And when he went to lunch, another mechanic, a blind one, completed the job. Anyway... I reset everything to factory specs and my gas mileage returned to normal. Most importantly, the cold idle returned to normal IMMEDIATELY and the DTC's cleared and stayed cleared.

Now that may not be the issue with your car, but given that the service manual calls for valve clearance checks at 104,000 miles OR 7 years (and your car is 7 yrs old right?) with adjustment ONLY if necessary and that many mechanics like to actually tweak the valves when the inspect it (so that they can ring up that $875 bill)... you may want to think about the possibility that your valves need adjusting. Again.

If you are a "good" weekend mechanic and are capable of this particular job, you might want to give it a try. Be prepared to replace valve cover gaskets (and those gaskets that fit around the spark plug tube.. and probably intake manifold gaskets). And be forewarned, the valves on the MDX are a bit tricky to adjust. Too much clearance and you'll hear noise. Too little and you have a check engine light on, low idling, low gas mileage, etc.

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oh.. and btw... I highly recommend you change your transmission fluid every other oil change. Do it yourself. Don't take it to jiffy lube or whatever. Buy 3 qts of the fluid (not 4.. but 3) from the dealer and use HONDA ATF Z-1 fluid ONLY!. The first few years of MDX's were built with substandard torque converters. It is a known acura problem and there are loads of service bulletins about this issue. Changing the fluid regularly will eliminate torgue converter rumblings and improve the lifetime of the transmission. It may also help the idling issue. And make sure when you change your oil (or get it done where-ever) you use 5W-20 oil ONLY.

To change the transmission fluid you'll need to get a 17mm socket with about 3 - 6" extensions to get the fill port on the top of the transmission open.. And the drain plug is just a nut underneath that 3/8" drive fits into. similar to an allen bolt only square and 3/8". You can't miss it. And you'll need a funnel with a 2 ft hose to fill the transmission fluid

cheers

Acura Mdx Exhaust

The 2004 MDX luxury SUV, which works on sale today at Acura sellers nationwide, will be priced at $36,400. The MDX with traveling equipment, which supplies you a roof rack, genuine cost Acura/Bose music device and different added good factors, will be priced at $39,000. The MDX with traveling equipment comes with 2 attainable production facility ideas: the Acura Navigation device with Voice acceptance priced at $2,2 hundred and the Acura DVD leisure device priced at $a million,500. in spite of distinct improvements, 2004 MDX expenditures reflect a modest a million.8 % boost, or $seven-hundred, compared to very last year in accordance with a sales-weighted prevalent.

My 2003 Acura MDX would start and idle good at cold temperature for a few good minutes, then right between warming up to normal engine operating temp range it would stumble, idle rough and sometimes even die. Occasionally I would get random multiple cylinder misfire trouble codes, and other times I would not even get a trouble codes. People pointed to the fuel injectors, O2 sensors, EGR, Coil Packs, VTEC control module and value and adjusting the valve train; however I check all these topics and everything seem to be ok. So what the heck could be the problems with this non-sense trade my car in topic! The last thing I looked at was the Drive by wire, (not drive by Cable) throttle body. I took it off because I wanted to clean the IAC valve, but discovered my touring MDX doesn t have this option, nor does it have a TPS since its drive electronically by wire, not the old fashion cable wire method. I noticed it did have a MAP sensor on the throttle body; therefore I took it off and found the O-ring was damaged and the sensor internal port was dirty. I cleaned out the throttle body with throttle body cleaner, (don t use carburetor cleaner) and also sprayed the MAP sensor until it was clean inside and out. I scrubbed the internal throttle body and blade with a soft cloth with throttle body solvent I sprayed from the can, therefore wiping all the carbon crud that was on the internal port and MAP port on the throttle body. Don’t use a wire brush or soft sandpaper to clean the throttle body since you could scare the port therefore creating new problems, just use a soft cloth with solvent to clean it up. I replaced the O-ring on the MAP sensor and sprayed into the throttle body coolant ports to make sure that internal chamber was clean too. Then after I remounted the throttle body and hooked up all the wires, coolant lines to the ports plus put the body air box hose back on. I reconnected the negative cable and started the engine, again the idle look good at normal cold startups when the temp gage is registering C. The test would be if it stumbled once I got down the block at the first stop sign like it always does, that is, between cold and warm up temp. I made it down the block at the first stop sign it was idling great! The next test would it still idle great to the next stop sign, which in fact it did! I drove it around with the AC on and off, stop and go to see if the idle still had any problems during cold or normal running condition. Everything checked out and the idle at fully warmed up stage sat right below the 1K mark on the tach. Before it would stumble between 500 to 700 RPM’s and idle rough. Now it’s idling very smooth and stable at less than 1K on the tach. I also noticed at high RPM it would hold back in shifting between 1st to 2nd gear and 2nd to 3rd gear. It doesn’t do that anymore and the shifts are much smoother.

In short, make sure your plugs are new, and then focus on your MAP Sensor to see if the O-ring is ok and the port is not clogged, plus make sure the internal MAP Sensor port is cleaned too. Don’t waste your money yet on fuel injectors, O2 sensors, EGR, Coil Packs, VTEC control module and, adjusting the valve train.

Total cost to fix this problem was less than $15.00 USD, I just purchased throttle body cleaner and one freaking O-ring! Since it is running good now I won’t trade it in until the wheels fall off!