Hey all,
A friend of mine just purchased a used 2006 4runner v8 about 3 weeks ago. 212,000km (131k miles). I went with her to test drive and purchase. All seemed great, little bit of rust but look pretty good considering the age and came with a few extras (3” Lift, new stereo Head Unit, Sub and amp. She got a good deal as the rear tailgate is rusted out and will need replacement.
I happened to take a look under the hood last week and noticed the coolant reservoir was pretty much empty. We topped it up and it continued to disappear. I briefly looked for a coolant leak and could not find any. Did not remove skid plates for a closer look but I could not smell any coolant as well. Mine had a leak and it was pretty apparent just by the smell. Anyways, dropped off at mechanic and his response is Head Gasket is leaking/blown. He has quoted about $3000 Canadian ($2300 USD) for “machining, spark plugs, timing, labor and gaskets.”
Being the weekend I have been able to get a batter description of some of these items but my friend thinks he quoted for replacing the timing belt and water pump while in there. The timing belt and WP were replaced about one year ago by the PO. The PO seems like a trust worthy guy and has been in touch about this issue and says he never had this problem. My gut believes him, but yes I know sometimes people lie. But for arguments sake let’s say this is a new issue.
The mechanic says this is probably the minimum amount and will not know more until he opens the head up. This mechanic owns a specialty shop in town that deals with Land Rovers and such (friends previous car was taken there too regularly.) Helped talk her into switching to a 4runner and now I’m feeling pretty aweful considering the situation.
Now my friend has not noticed any spike or irregularity in the engine temp so I’m hoping we caught this early enough that no damage was done. I do not recall seeing white smoke come out of the exhaust but never really looked for it. And the vehicle ran great and gave no sign a cylinder was misfiring or anything else. Just happened to see the coolant was low. Which again makes me hope that we caught it early enough.


Does this quote seem accurate?
Do these items seem necessary? (Will update when we can talk to the mechanic again on Monday as to what exactly he’s suggesting)
Should we get a second look from another shop?
Is machining the heads necessary/recommended?
She’s thinking of waiting on the Timing belt and WP to save money at the moment as that would really only buy an extra year with it.

Any advice or thoughts would be appreciated.

Did the previous owner replace the timing belt and water pump himself? There's usually a sticker on the plastic engine cover stating it's been replaced if he took it somewhere. Maybe the coolant could be leaking from the water pump. Does the oil look fine?

Get this and test: Block Tester BT-500 Combustion Leak Test Kit - Made in USA https://www.amazon.com/dp/B06VVBSFTF..._xG3eBbDGFNWWR

Also check radiator for leaks.

I the work was done by a shop and the sticker is there. I did not get a chance to thoroughly look through it before it was taken to the mechanic. Did check the oil the day before and I don’t recall it looking off. Wasn’t looking for it but I feel I would have noticed murky oil.

The mechanic mentioned the coolant is leaking into the oil and is burning off out the exhaust. He says the signs were moisture in the tailpipe and white smoke.



I will look into this if she decides to go a cheaper route and try and source the issue herself. Thank you

We used one of those on mine and it came up negative. A cheap ebay/amazon borescope confirmed coolant in #6.

I would do the best oil analysis I can find which would be Terry Dyson:
Dyson Oil Analysis Reports

Will confirm whether there is coolant in the oil definitively. I would say this is not the time to hope the mechanic is right and try something off amazon. Get the right info and decide.