Phantom head gasket leak

I’m new to Tacoma’s. After sitting for many days on startup runs roughly until it warms up. Throws a check engine misfire code, which can be cleared. Regular daily driving does not manifest this problem. Dealer says it needs a head gasket. #3 cylinder leaking. No overheating episodes.

I find no evidence of oil in coolant or coolant in oil.

Anyone have any experience with this problem? 2003 3.4 six

Appreciate any help. Generally running fine but I don’t want to fry the motor.

Thanks

 

Could be losing compression through the gasket into another place, not necessarily a water jacket or oil passage. Get a second opinion, if you can, to confirm.

 

Good advice. Thanks Mike

 

You're Welcome!

 

if it is reproducible on a regular basis and you know the cylinder take the spark plug out the evening before and let her sit. In the AM have someone else start her up and put you hand over the plug tube well and see if there is coolant / vapor blown onto your hand.

 

Good idea, thanks

 

Well, time to start the sh!t storm of "that's junk/never works" comments....

Before you pay the money to do head gaskets -especially at dealer prices- there is a something IMO that's worth a shot. *Disclaimer- I have ZERO to gain and no association with the company. Just sharing info others may find helpful.

There's stuff called Blue Devil head gasket repair. It's $30-50 depending on the bottle size. Here's the backstory of why I'd even try it. Ford small blocks have head gasket issues in high cylinder pressure applications (boost or nitrous normally). Some of the low buck NHRA Ford nitrous guys use this stuff as an emergency effort to fix a compromised head gasket between rounds. If they don't have the crew, parts etc it's a reasonable gamble to get them back to the starting line. It doesn't always work, but very often it does-and those gasket leaks are far worse than what you're describing probably is. I asked a few guys about it, as I'd always been told the "no such thing as head gasket repair in a can". They all gave the same story-seems to be pretty harmless, works quite a bit of the time, and generally well worth the price considering the gaskets alone would run more than the can.

I got my current Taco for $1500 with a blown head gasket. Owner popped a heater hose and pee'd the coolant out, overheated it and melted the gasket. Obvious miss at all rpm's, code showed the missfire, hell it still had the bad hose on it when I towed it home.
Original plan was swap the motor out for my known good 4r 3.4. I figured it was worth a $40 bottle of Blue Devil to gamble not having to pull and swap the motor. Worked like a charm, have had zero problems. Running a supercharger on it now too.

Depending on budget, if you need the truck daily right now, etc it may or may not make sense to try. I was awful busy at the time so it was a decent gamble to try. If it let's go again I'll swap the motor as originally planned.

Good luck either way!

 

A compression test is required here for sure. Are you having to add coolant at all? Are you sure the spark plug and threads are good on that cylinder? Plugs have been known to leak around the gasket ,insulator or threads. Has it been overheated recently? I have used K&W block seal with success in the past, similar to the post above. It may be worth a try if indicated but you must follow instructions exactly. It also could be a bad valve or seat, weak or broken valve spring, a cracked head or other mechanical problem on that cylinder too. If you put compressed air into that cylinder with the valves closed (top dead center), you may hear the air escaping from the intake or exhaust or bubbling into the radiator. I think "needs a head gasket" means we take it apart and see what we find instead of trying to determine what's actually wrong first.

Edit: Do not rule out a fuel injector related problem here too. The injector may be leaking fuel into that cylinder overnight making a temporary misfire.