Questions as I'm doing a head gasket job - 1GR-FE 4.0 V6

Background: 2005 - 4wd dcsb - 4.0 V6 - 180k miles

I'm an amateur home diyer. I do minor repairs myself but an HG job is far out of my comfort zone. I called a few shops and they wanted to replace my engine instead of doing the HG job. So I thought I might give it a try myself and worst comes to worst, I need to replace my engine.

I'm in the middle of doing a HG job currently. After being in denial, I concluded this is the only thing that is left for me to do so... here we go... A little background on what I experienced and replaced before accepting it might be the head gasket.

• Symptoms
  • Occasional engine misfire codes
  • A lot of steam from the exhaust (although could be cold days)
  • Coolant has been running low. Strangely, the reservoir seems fine (even on cold), but when I open the radiator cap, I can usually fill a lot of coolant in the radiator. Not sure why it wasn't sucking up coolant from the reservoir.
  • Coolant reservoir started having bubbles on idle.
  • Overheated a few times but always stopped before it got too close to the H
  • No chocolate milkshake so oil and coolant has not mixed yet.

• Replaced items before concluding it was the head gasket
  • Radiator cap
  • Thermostat
  • Water pump
  • Radiator
  • Clutch Fan

Questions: A few questions for your experts...

1. Carbon Build Up - I'm seeing a lot of carbon build up on only once side of timing chain cover (cylinders 2,4,6). Is this indicative of anything in particular?
   
2. Cleaning Carbon Build Up - I want to clean this up before putting back on. Any issue using carb cleaner or brake clean to clean off carbon deposits on timing chain cover and valve cover gasket before putting back together?
3. Wear marks on cams - Got a few spots on camshafts that show wear. Is this normal?
4. Any other tips or things I should look out for while I have everything open?
5. Any signs that this engine is a lost cause already? hahaha

Pics:

• Timing chain cover carbon build up
  • 
• Camshaft adjuster carbon build up
  • 
• Camshafts top down
  • 

Thanks ahead of time for any tips!

 

I am no expert but I replaced the head gaskets on my 08 4.0L V6 a few months ago. I have a thread that I posted on TW so hopefully you found that. You never mentioned how many miles are on your engine.


Questions: A few questions for your experts...

1. Carbon Build Up - I'm seeing a lot of carbon build up on only once side of timing chain cover (cylinders 2,4,6). Is this indicative of anything in particular?

I didn't take many pictures of my parts before cleaning, but the LH (driver's side) did have more oil buildup. I was told that there is typically a discrepancy from side to side as the PCV is on driver's side.

1. Cleaning Carbon Build Up - I want to clean this up before putting back on. Any issue using carb cleaner or brake clean to clean off carbon deposits on timing chain cover and valve cover gasket before putting back together?

I can't really help with this one. I just used parts cleaner to clean the surface of any oil and loose debris. The staining and varnish didn't bother me. I think you need to use an actual parts cleaning machine to do a better job.

1. Wear marks on cams - Got a few spots on camshafts that show wear. Is this normal?

There will be some wear depending on the miles. The wear I observed on mine was smooth and shiny in appearance. No pitting or gouges. The SM describes how to check the cams for excessive wear although I didn't bother. All I did was check valve clearances.

1. Any other tips or things I should look out for while I have everything open?

I think you will get varying answers here. Depending on your miles, a lot of folks will say to replace the timing components while you have it apart. E.g., chains, tensioners, sprockets and guides. Even if you buy those from an online dealer, that will cost close to $1000. If you are going aftermarket, good luck. If the main tensioner isn't super extended and you have no timing codes then I would leave those alone. I read somewhere that you should make sure that the color coding on the chains are visible. Supposedly overheating the engine will sometimes remove the markings. I don't know how true that is. Might be an "old wives" tale. Btw, the SM does show you how to measure the chains, sprockets and guides for wear. I checked all of mine expect the chains due to not having the correct tool to check those. You will be resealing the motor using the valve grind gasket kit so that will take care of any leaks you may have had. Throw in a set of spark plugs. I see you already did the water pump and thermostat so reuse them.

1. Any signs that this engine is a lost cause already? hahaha

That's the million dollar question. You may have warped the heads beyond resurfacing due to the overheating. You will not know until you get them checked.

 

@zguy1 thanks so much for taking the time to post links and comprehensive response.

2005 - 4wd dcsb - 4.0 V6 - 180k miles are the specs of my truck.

Everywhere I called wanted to replace the engine instead of doing a HG job because of liability so I’m looking to get out of this in the cheapest way possible or else I might as well put that money into a new engine. So I’m in it for the toyota head gasket and seal kit. Will check tolerances and hopefully nothing is warped.

Will be looking into your post. Thanks so much for the response!

 

If you didn't overheat the engine your heads will most likely be fine. But take it to a head shop for a rebuild and check. I did this for them to check the valves as well.

For cams and buckets, If there are no signs of galling and you can't feel any of the wear marks with a fingernail then the cams are fine.