Head Gasket/Head vs Rebuilt Motor - Page 5 - Toyota 4Runner Forum

brillo_76 · 03-01-2023, 09:16 AM

Quote:

Originally Posted by Langcow1

It’s running great now. It could just be in my head but it seems like it has more power since I switched the Denso sparkplug wires to NGK

You have more power because all your injectors are working properly.

Sent from my SM-A536V using Tapatalk

Daryl Elmore · 03-01-2023, 11:32 AM

Slothy, I had the exact same symptoms as you, rough cold start, clears after a few seconds. Also had smoke out of the exhaust during startup but its cold here in Idaho so that may have been the cause. after a compression test and testing the coolant for exhaust gasses #4 was down to 165 and the others were all 185-200 so I pulled the left head. End result was 2 cracks between the valves which seems to be not uncommon. New head and gaskets and she's back running great. When I pulled the head, #4 piston was clean compared to 2 and 6 which was the dead giveaway coolant was getting in.

Sparman · 03-01-2023, 06:27 PM

Quote:

Originally Posted by Daryl Elmore

Slothy, I had the exact same symptoms as you, rough cold start, clears after a few seconds. Also had smoke out of the exhaust during startup but its cold here in Idaho so that may have been the cause. after a compression test and testing the coolant for exhaust gasses #4 was down to 165 and the others were all 185-200 so I pulled the left head. End result was 2 cracks between the valves which seems to be not uncommon. New head and gaskets and she's back running great. When I pulled the head, #4 piston was clean compared to 2 and 6 which was the dead giveaway coolant was getting in.

I have the same experience as Daryl, except my problem was a head crack between the valves over the #3 cylinder. It really wasn't a tough job. If you've done a timing belt job and valve cover gaskets, you've covered 80%+ of the job. Other than that, it's removing exhaust manifolds and heads. Plan your parts list, set aside two full weekends, watch Tim's videos and Chigger's videos, and you can knock it out.

Langcow1 · 03-12-2023, 04:19 AM

Quote:

Originally Posted by brillo_76

You have more power because all your injectors are working properly.

😄 Yep definitely better than when it was misfiring! I wonder though if it was subtly failing for a while before the misfire started and I was losing a little power from it. It definitely feels like more power now than before the misfire, so it’s either that or the Engine Restore additive really had a positive effect.

Today I finally got the crusty old fuel filter changed. That seems to have made a positive impact too but how much I can’t say.

toverturf · 03-30-2023, 08:48 PM

I feel like I have the same issue as I'm starting to have the same symptoms. Going to confirm it here soon with a leakdown test and coolant system pressure test. If my compression test comes back good i'll probably just replace the head(s) if it's cracked. Does anyone have a good place to recommend getting new heads at?

gamefreakgc · 03-31-2023, 02:35 PM

Quote:

Originally Posted by toverturf

I feel like I have the same issue as I'm starting to have the same symptoms. Going to confirm it here soon with a leakdown test and coolant system pressure test. If my compression test comes back good i'll probably just replace the head(s) if it's cracked. Does anyone have a good place to recommend getting new heads at?

There are not any brand new cylinder heads outside of Toyota that I'm aware of due to the complicated process of casting and manufacturing cylinder heads. There are some high quality remanufactured/refurbished cylinder heads such as Yota1's product here at a rather decent price:

5VZ OEM 3.4 Reconditioned Cylinder Head 95.5-04 - Yota1 Performance, Inc.

Outside of them, honestly your best bet is pulling one off an old junkyard unit, buying new valves, springs and seals and sending it to a machine shop for assembly and testing.

mudbug87 · 04-01-2023, 04:12 PM

Welp! It looks like my head gaskets have gone too. Whats weird is that when I did a leak down test cylinders 3 and 4 resulted in a geyser from my radiator. The rest of the cylinders were great.

Is it common for the gasket to go out on both sides of the engine? Also does anyone have a sense for how common it is for the gasket to go out vs a cracked head?

I have never over heated the engine and overall it runs like a champ.

PS sorry if this is thread high jacking, but I dont have the privileges to make my own post yet.

brillo_76 · 04-01-2023, 04:28 PM

Quote:

Originally Posted by mudbug87

Welp! It looks like my head gaskets have gone too. Whats weird is that when I did a leak down test cylinders 3 and 4 resulted in a geyser from my radiator. The rest of the cylinders were great.

Is it common for the gasket to go out on both sides of the engine? Also does anyone have a sense for how common it is for the gasket to go out vs a cracked head?

I have never over heated the engine and overall it runs like a champ.

PS sorry if this is thread high jacking, but I dont have the privileges to make my own post yet.

It can happen. See if you can rent a botoscope or buy one that attaches to a cell phone and look in the cylinders you know are bad.

Why it's not as noticeable is both cylinders are directly across from each other and kinda balancing the loss out.

Sent from my SM-A536V using Tapatalk

mtbtim · 04-01-2023, 10:16 PM

Quote:

Originally Posted by mudbug87

Welp! It looks like my head gaskets have gone too. Whats weird is that when I did a leak down test cylinders 3 and 4 resulted in a geyser from my radiator. The rest of the cylinders were great.

Is it common for the gasket to go out on both sides of the engine? Also does anyone have a sense for how common it is for the gasket to go out vs a cracked head?

I have never over heated the engine and overall it runs like a champ.

PS sorry if this is thread high jacking, but I dont have the privileges to make my own post yet.

@infamousRNR and I will be working soon on a head gasket video series. Stay tuned.

gamefreakgc · 04-03-2023, 03:07 PM

Quote:

Originally Posted by mudbug87

Welp! It looks like my head gaskets have gone too. Whats weird is that when I did a leak down test cylinders 3 and 4 resulted in a geyser from my radiator. The rest of the cylinders were great.

Is it common for the gasket to go out on both sides of the engine? Also does anyone have a sense for how common it is for the gasket to go out vs a cracked head?

I have never over heated the engine and overall it runs like a champ.

PS sorry if this is thread high jacking, but I dont have the privileges to make my own post yet.

It's more common for the gasket to fail as it is a weaker failure point than the aluminum heads. However it is good practice to have the heads pressure tested and milled flat at a machine shop (less than $100 per head) before reinstallation and they will tell you if it's cracked so you don't accidentally put a bad head back on.

Site Navigation