2004 Limited Edition 4Runner 4X4 - Head Gasket

[paulrits]

04 V8 4.7L Head Gasket Replacement.... at what cost?

My 2004 V8 4.7L is having the exact same issue and I am looking for some guidance. It was idling rough and running rough between 60-70mph. The mechanic originally diagnosed cylinder #6 misfire and replaced the plug and coil.

The issue continued and they finally came back with the head gasket needing to be replaced ($2k). I am slightly concerned to have the dealer replace the head gasket on an older higher mileage engine (196k). Concerned with too much compression on the old engine after they replace and reshape the heads. Is this a valid concern, and what would your suggestions be? I thought about trying to just find replacement engine, would that be a better option?

 

[Lineman8]

Smell in overflow tank

Is an exhaust smell in the coolant overflow tank always a blown head gasket? I don't have any other signs that were mentioned here, and no codes or anything. I just bought a 2005 with 158k a few weeks ago. I was messing around after waxing it today and when I smelled inside the overflow I thought I smelled exhaust. I'm afraid I got ripped off. I love the truck and am praying there's a chance there's nothing wrong here and I'm over analyzing. I also noticed some light sediment or something in the coolant expansion tank. I was thinking about trying a coolant flush and hoping for the best. Any advice or input is greatly appreciated.

 

[Supersonic]

Let me guess no. I'd say change the coolant if you can't verify it's ever been changed. Probably just normal use smell considering what the coolant's job is.

Consider the thermostat temperature rating too, get one that is rated a few degrees less and change it out so the engine runs at a cooler temp, but is still in the range of not setting any computer codes.

One of the best mass produced vehicles on the planet, so unless they charged you double what it's worth retail, you got a good deal even at worst case scenario of changing a head gasket. Enjoy it and buy an inexpensive Corolla to get you through any sidelining maintenance.

 

[cpayne5]

Is an exhaust smell in the coolant overflow tank always a blown head gasket? I don't have any other signs that were mentioned here, and no codes or anything. I just bought a 2005 with 158k a few weeks ago. I was messing around after waxing it today and when I smelled inside the overflow I thought I smelled exhaust. I'm afraid I got ripped off. I love the truck and am praying there's a chance there's nothing wrong here and I'm over analyzing. I also noticed some light sediment or something in the coolant expansion tank. I was thinking about trying a coolant flush and hoping for the best. Any advice or input is greatly appreciated.

The presence of hydrocarbon gases in coolant indicates any combination of the following... cracked/warped cylinder head, cracked block, faulty head gasket.

I wouldn't trust your nose test, though.

Get one of these, or go to a shop and have them perform a test with one...
https://www.napaonline.com/en/p/BK_7761077

No use speculating when a proper diagnosis will give you the correct answer.

Hopefully you're just paranoid.

 

[Lineman8]

Thank you two for the responses. I'm getting the undercarriage sprayed tomorrow at a mechanic in NH. Going to talk with them about it some more. I posted in another thread as well, the "request for action" one. Have a pending code on cylinder 6 which I discovered this morning, which isn't the best news. Keeping my head up! Got a fair price on it, and after looking at some numbers, the cost of the repair still makes it worth it. I want to keep this thing on the road for another 10 years hopefully.

 

[bmitch]

2004 SR5 with 170K miles

Symptoms include gurgling noise behind the dash, engine shake on cold start (has only happened 4-5 times at this point and only lasts for ~30 seconds), initially had a CEL pop up for an O2 sensor, cleared it, and 2 weeks later now have another one that's popped up. I'm probably only driving the car 60 miles a week at this point.

Have not overheated the engine and coolant levels are still above the low line

Two questions:
1) Should I go ahead and replace coils / plugs (assuming CEL is for a misfire) or I am doomed with a blown gasket?
2) Assuming I keep coolant and oil levels within range, do I really need to replace the gasket?

This is frustrating, as my 1986 FJ60 still has great compression after 260K miles, and hasn't needed a head gasket yet!

 

[cpayne5]

My advice is don't jump to conclusions.

One step at a time. Step one is to pull the new code. Go from there.