Plug located on motor

Okay so I have a 2002 toyota 4runner sport edition with the V6 in it and on the driver side of the motor right above the oil fill cap there is a plug that for some reason there is nothing plugged into it. Could anyone tell me what this is and could this be a reason why my truck is running beyond rough. I just bought the truck for $400 the guy told me it had a blown head gasket so I don't know anything about the truck seeing as it's only been mine for about 3 days. Thanks

 

A picture will help in understanding what you're referring to. Above and to the right of the oil filler cap, I believe the #2 cylinder spark plug gets connected. If it is a blown head gasket I can see why someone might have removed the plug to see the evidence but again a picture will help.

 

It's right there at the side of the intake manifold

 

I think this is the data link connector or what Toyota refers to as DLC1 for this engine

 

Will that cause it to not run correctly

 

It is a diagnostic port. I have not used DLC1 but you'll need a Toyota scanner. There may be adapters that may allow you to use a standard scanner with DLC1. You can google this but by shorting some of the terminals, you may be to see some faults with the way engine check light will flash or measuring resistance, ..., etc. The better way is to use an OBD scanner tool and attach that to the OBD diagnostic port that is above the gas pedal (below the dash) and read the codes. I am not familiar with the capability of diagnostics on a 2002, but perhaps you can see which cylinder is not operating. In this instance, however, since you've been told the engine has a blown head gasket, that would be the primary reason as to why the engine is not running correctly.

 

Okay yesterday I tried or attempted to do a flush system flush on the truck because the inside of the radiator is like this Orange looking it looks almost like rust but that same stuff that's inside the radiator is all over everything up under the hood like the whole motor and everything up under the hood is covered in this orange rust looking stuff so I got the truck to idle at a semi okay idle yesterday it's still idling super low and the exhaust was coming out of the tailpipe until the truck got warm and then it's like the exhaust quit coming out of the tailpipe and started coming out of the upper exhaust system up towards the motor instead of making it all the way to the end of the tailpipe but I still couldn't get it idle at a suitable idle to even begin to do a flush on the system. I was suggested by a mechanic to get the blue devil head gasket repair put in the truck to see if that would seal up the head gasket because currently I don't have the money to completely replace the head gasket on the truck but I can't even begin to put any blue devil in it if I can't flush the system out I changed the oil in it yesterday and before I even crunk up the truck to start doing the flush there was already water in the oil that I had just put in there so I'm just looking for some advice on maybe if that tells me something other than just a head gasket or if that tells me that the blue devil is not going to work at all or how I can even go about doing this without cracking the head or messing the truck up even more

 

Wow, looks like at the very least you have a head gasket that needs replacing, ASAP. Your probably not going to get around this , bite the bullet now. Just my humble opinion

 

Gasket sealers may work when the issue is a small crack in either the gasket or the head and even then it is a temporary fix. This sounds like a significant failure if you immediately saw water in the oil. In this instance I very much doubt that blue devil will do any good. Having said this, the issue may not necessarily be limited to the head gasket itself. You may also have a warped head or a cracked head. If the vehicle is in a good shape (i.e worth saving), you should plan on having it repaired properly. It is a lot of work and I am afraid expensive.

 

Yea that is what I was afraid of. The night I bought it I met the guy looked it over and for $400 considering the shape the truck is in I decided it was well worth $400 cause a toyota that don't run at all go for a lot more than that where I live. And I know that if a toyota is taken care of properly they will last forever. I started the truck with the guy standing there and noticed it was running rough but I didn't want to just let it run so I turned it off quickly. I got ready to get it to the house (reminder the guy had hauled ass) and I had to back it up to hook it up to pull it and I started giving it has to back it up and it smoked the whole parking lot out immediately it looked as it were burning to the ground I could not see the car parked next to me. I should have known there was a reason the guy I bought it from hauled ass. How do I inspect the head to see if it is actually cracked or warped?

 

The only way to properly diagnose this is to pull the head and to measure with a straight edge and visually inspect for any cracks which may not be readily apparent to the naked eye.

 

I am afraid the only way to really know whether the head is damaged or not is to remove it and have it pressure tested at a shop. Sometimes a crack is visible and in that case a test will not be needed. Sometimes a head may be warped and the machine shop can resurface it if it is within the allowable tolerances. Again if the vehicle is worth saving, you can ask around and see how much they charge for a head gasket replacement. I don't have a clear idea how much that would be but I suspect anywhere in the range of $1200-$1600 (labor & parts) for one head. If both heads need to be fixed then the cost will go up some but I suspect only one head gasket has gone bad in this case. You can certainly run a compression test and see which cylinder(s) is low on pressure and that will tell you which side. Alternatively the OBD tool may also help except I don't know whether a 2002 model will display data on cylinder health or not.

If the head is damaged, then you'd be looking at another $400-$800 for a used-new head. Finally since all the components on top and front of the engine will be out, you'd be better served to have the timing belt, water pump and all the oil seals replaced. You will certainly save some labor dollars but fork put extra for parts. If the timing belt on this vehicle has not been replaced in a while or ever, that will also be a good thing to do.

 

One other afterthought. Since you don't know the history of the vehicle (ex: how long did previous owner run the engine with the bad head, for how long did the engine run with the coolant seeping into the oil circuit, what caused the head gasket to go bad in the first place), there is a chance that other damages might be present that become known once the repairs are started.

 

Yea there is this rust looking stuff all over everything under the hood

 

That's a diagnostic port that usually has a cover on it.

You need a new mechanic.

I think its pretty unlikely the block is cracked but it sounds like you do need a head gasket replacement asap before you drive it anymore.