If someone has any knowledge of this it would be appreciated.

I was driving home last night and my check engine light came on. I wasn't over heating or low on oil. I then proceeded to take the closest exit off the parkway and go to a gas station to check under the hood.
Where the hose comes off the top of the radiator and goes to the engine block I noticed fluid under the hose on the plastic housing.

Now the odd part. I grabbed a paper towel and wiped it and it wasn't antifreeze it was transmission fluid. It looked like the hose from the radiator was fine and not leaking. With the plastic hosing on the front of the engine it was tough to see what was behind it. I did notice it was wet with transmission fluid around the metal adaptor to which the radiator hose clamps onto that is bolted to the engine.

Does anyone know if there is a transmission line running along the front of the engine?? What is exactly behind that plastic housing with 3400 written on it.

Sorry so long winded but it is hard to explain because it is such an odd occurence.

Thanks for any help,
Dan

Behind the plastic shield is the timing belt and water pump. As for the check engine light, you need to get the code from autozone or the dealer to really identify what the issue is. I think the trans fluid you are seeing is another issue...unless you are seeing A LOT of it.

It is possible you have a powersteering leak (same fluid) or a line to a transmission cooler is leaking. Neither one will throw a CEL.

Get the code and we can go from there. Did it ever go back off?

Thanks much for the reply.

I never really noticed any puddles or anything so it isn't pouring out. I noticed when I opened the hood last night that this had to be leaking some over time because of older residue on the housing.

It wasn't that bad last night but I did drive it here to work and when I checked underneath the hood again, it looked a little worse already.

I have not gotten any codes and the engine light never went off. Does the transmission cooler hoses run under there as well? from the looks of it, it only will leak when driving and it looks to be probably squirting up.

Dan

The codes are stored in the computer. The only way to get them out is to use a diagnostic machine which can read the codes. Some Autozones will do this for cheap or free. If the CEL is on ... you have a code that will help diagnos the problem.

As for the leak, try and take a picture of where it is coming from and post it. We can help you identify the source....in fact, take a few pics.

Are you sure it was ATF? Factory Toyota antifreeze is red, just like ATF.

Well, sorry it took so long to get back. To answer the question about the ATF, it was antifreeze, the extended life which is a different color. I "used" to be hip on cars/trucks but haven't done my own work to my vehicles in years. Sooooo, I had no idea they would make that color look so close to trans fluid.


About the check engine light, I did get the computer read. Of course I left the codes at home I believe they were P0171 and P0172?? That is a close number if not the ones.

I did bring it to a garage because of the leak so I had them check the computer. They gave me all the paper work on what the computer told them to check and he couldn't find anything that was wrong.

Some of the things that were listed had to do with fuel and mass air flow sensor, check oxygen....can't exactly remember. So, they went all through that and reset the computer. I drove it for a day and a half and when I was on the parkway again, going around 75 the light came on again.

The truck doesn't seem to run any different. I am hearing alot about gas caps. Do you think a bad gas cap could be setting this thing off???

I changed the gas cap yesterday but I don't know how to reset the computer on the SUV.
Does anyone know how to do this?? All help is appreciated.

Thanks,
Dan

Hi Dan,

You can reset the check engine light by pulling the EFI fuse. The fuse box is located just behind your battery. While you're at it, you might want to try cleaning your MAF sensor. I was getting a check engine light a couple of weeks ago and couldn't figure out what it was. Cleaning the MAF sensor fixed the problem. The following article will help.

Link

agreed, clean your MAF, clear codes, and drive. If it comes back on we can start talking about O2 sensors.

They are common on the 3.4L v6 and are caused by the MAF getting dirty.. Clean it per the above link...


A little more information about the PO171 and more about the systems in general

And a gas cap that is not air tight will set off a code. If the system can not pull a partial vacuum on the gas tank after 20 minutes of driving, it will set the code.. I believe its PO456... have to look it up to be sure..

Ditto on "clean the MAF". Meanwhile, it'll re-trigger the CEL during higher loads on the engine. You have to carefully but thoroughly clean those fragile wires that are way down inside the sensor itself. See the link above.

Also that same P0171 or P0172 code can be caused by leaky TRD headers when their crummy gaskets fall apart after a year or two and cause a header leak. They now use a different type of gasket, plus I used lots of gasket maker to help hold the new rubber gaskets in place. If you don't have TRD headers, you can obviously ignore that suggestion.