Is it the head gasket? 2005 V6

Hi all,

I have a 2005 V6 with 208k miles on it. A few weeks ago the CEL light came on together with the VS track and VSC. I thought it's the gas cap issue, so I did the "reset" (turned the cap until it clicked once, disconnected the battery for 5 min). Lights went off, but then a few days ago they came back again, then yesterday they went off now it's on again. I also noticed that a little coolant disappeared from the coolant tank (about 1 finger in 600 miles of driving). Today I had the codes read and it gave me P0306 Cylinder 6 misfire. Also, I have a rough idle for not more than 5 seconds, but not every time, only sometimes. Otherwise the car drives great, no overheating, no smoke, oil looks clean, coolant looks clean. Is it the head gasket or I have hopes that it's something less expensive, such as water pump and the intermittent rough idling is actually spark plugs and coils? One can only dream...

Thanks!

 

There is a chance that your gas cap is bad and not sealing properly. My Corolla had the same lights and after I replaced the cap, the lights never came back on. It read a bunch of codes but it was the cap after all. Try that first. It is the cheapest fix. If it happens again then go for the plugs and wires. From what I understand, the best sign of the head gasket going is white substance in the coolant. Good luck.

 

My guess is you have two separate issues going on.. one is the gas cap, the other is the missing coolant. Being that you have a 2005, my thoughts go to head gasket. You can try to do basic things to try and help the bad idle, but spark plugs and coils don't make coolant disappear.. if you can't find any other leaks, it's got to be going somewhere, most likely into cylinder 6 and out your tail pipe. Check your weep hole, bottom corners of the radiator, all your hose connections, overflow tank connection, etc. Definitely do the due diligence to rule out other things, since it sounds like it's a small amount going missing for now and you probably have time before it gets worse, if it is actually a head gasket.

 

A whole finger worth is not a small amount of coolant loss, you should be able to easily see if the rad or other places are leaking, if not wet it will be a pink crusty residue.

Gas cap will send a specific code for emissions evap, it wont or at least shouldn't trigger a misfire code in a cylinder. When you unplugged the battery that cleared the codes but then they came back, most likely not gas cap related.

Being a 2005 chances are it's a head gasket, there are testers that can determine if there is combustion gas in the coolant, it wont always cause milky oil or white substance in coolant.

Best of luck finding what it is but if it is a head gasket dont go to a dealership for repair, a competent shop or mechanic can do the same work for far less $$.

 

I'm finally admitting defeat and having the gaskets done on my 05. Last thing I want or need is a blown motor. I'm also getting the heads completely rebuilt and installing a brand new oem chain....and everything timing chain related. Guides, sprockets, tensioners etc and the water pump, even though it's relatively newish.

And this coming from a guy who believes in the old adage, don't fix it if it ain't broke.

 

Official welcome

 

How much all that gonna cost ya ?

 

1k labor.
825 for all oem timing chains and parts, including a new Aisin water pump.
100 bucks for the revised head gaskets from Toyota.
About 250 for the Felpro gasket set. Just not using their head gaskets.
350 to go through and rebuild both cylinder heads.
45 bucks for new head bolts.

So about 2700.

It helped a lot that I started buying all the parts a couple months back. But keep in mind that I could prob have saved money by reusing the timing chain. Wasn't too much wear when mechanic checked it out, but I just wanted all new stuff in there. I do a lot of driving for pleasure. Better safe than sorry.

 

For future reference. Pull the spark plug. They usually tell the story of why the misfire happened.

I hope you aren't going to be too mad when it happens again after all that work.

The Mechanic, a good one, should still take a quick look to determine what the root cause is and rule out common culprits like a bad coil pack or plug or wires or injector....or he's liable to be looking at an angry owner.

 

But my coolant gets lower, plugs and coils brand new, exhaust in the coolant, and the occasional misfire codes p0304. Pretty sure it's a head gasket.

Thx tho.

 

You confirmed exhaust in the coolant?

I don't see that in this thread. I must be blind.

 

You aren't blind. I posted that in another thread. I was just in here replying to another post. You know, trying to add quality content...maybe commiserate a bit.