I have a 1993 4Runner, V6 3.0L engine. Has almost 170K miles on it.

I think the head gasket is blown. I was driving it on the freeway when the temperature gauge on the dashboard suddenly spiked to the red (hot) zone and steam started coming out of the trunk. Pulled over, saw that white smoke was coming out of the exhaust (but no smoke was coming out of the engine). Checked the oil dipstick and there's coolant in the oil system (oil is usually amber to dark brown, now it's tan color).

I had it towed back home and haven't driven it since. This is my spare car and I don't drive it very often anyways.

I'm not completely sure it's a head gasket problem but based on the symptoms, I'm confident it's a blown head gasket; it must have delaminated between the oil passage, coolant passage, and the cylinder.

I shopped around and called over 10 auto repair shops to get some estimates. The cost range from $2800 to $4900. I'm wary of the low end estimates because I suspect they gave me a low estimate because they know there will inevitably be other parts or repairs that need to be done, and then they will add them to the repair cost. Since the engine is already broken down, I don't have an alternative to take it to another place easily.

Most of the repair shops though said that they will cover these repairs/parts as part of their costs:
- Replace head gasket
- Repair the cylinder head and have it resurfaced at a machining shop
- Replace valve cover gasket
- Replace engine thermostat
- Replace spark plugs
- Replace intake manifold gaskets
- Flush the oil system
** These estimates assumed that I could repair/reuse the cylinder heads. Having to replace them would cost about $1800 more.

There were two shops that stood out because their responses were off.

1) One shop said that they could fix the head gasket problem but they recommended that I replace the engine with a rebuilt/refurbished engine. The owner said that he had done 10+ head gasket repairs on 4Runners but he said that in his experience, the lower engine block was usually warped and he could not resurface the lower engine block without removing the engine. He just repaired the cylinder head and even though he installed a new head gasket, problems arose within a year and he had customers come back and complain because the engine was leaking oil. He said that he's reluctant to do head gasket jobs on 4Runners because of this.

I'm skeptical about this because if the lower engine block was warped, shouldn't any mechanic refuse to fix it because a warped engine block is beyond repair?


2) Another shop said that they would remove the cylinder heads and check for cracks or warps. But they said that they would not resurface it unless it was warped because Toyota recommended that the cylinder heads do not be resurfaced unless it was warped. (If they are cracked, then they are obviously beyond repair).

So I have two questions I would like to ask here.

Q1) Is it true that Toyota recommends not resurfacing the cylinder heads at a machine shop if they are not warped?

Q2) How likely is it for a 4Runner engine that has a blown head gasket (at about 170K miles) to have its lower engine block warped? And if it is warped, is it beyond repair for a blown head gasket? Or would installing a new head gasket with a good cylinder head overcome the warping problem?

Looking for some clarification here. Thanks in advance.

 

The 3.0 is known for blown head gaskets, you say "had it towed home and haven't driven it since", how long has that been?
the longer it sits the worse it will be, coolant/water in the oil will corrode everything in the bottom end, bearings included.
The block is cast iron and the heads are aluminum, so the heads are far more likely to warp than the block, when the heads are removed a precision straight edge can be used to check the block for warpage.
If you haven't already located a mechanic or shop that you trust there isn't much to go on, just remember "Cheap, Fast, or Good, pick any two". Cheap Fast. work won't be any Good. Fast Good work won't be Cheap. Cheap Good work won't be Fast. When you talk to a shop ask about guarantees/Warrantees. If they cover up to a year make sure to inspect everything for leaks at month 11. If they offer the "tail light warrantee" or the "Michigan 50/50 warrantee" (if it breaks in half you get to keep both halves) look somewhere else.
You may also consider doing the 3.4 swap, it also won't be cheap, but you will like it more!

 

Your engine is toast. I'd get a re-manufactured one like a Jasper as they come with a good warranty. If Eric O from South Main Auto likes them, then they are good stock replacement engines. Don't go pot luck with a local rebuilt. Have a Jasper rep shop install it.

 

My $0.02... Issues with having the engine repaired: Nowadays, heads are aluminum, blocks mostly cast iron still. Different expansion rates with challenges to establish a good durable seal. Surface finishes on the head in particular are critical. Finding a good machine shop is a real challenge. If you got it shutdown right away, I'd guess that the block is not warped. However, to find out, at least the "at issue" cylinder head has to come off. For guys like me (used to be, I'm old now) you do it yourself. In that situation, you have time to check things out. When you're paying shop rates the bill goes up fast.

In your situation, I'd agree with JoeS. Just to note: the independent two-man shop, that has been repairing my '89 pickup for many years, does excellent work. Last time I was in their shop, they had a Jasper Engines ad poster on the wall in the office, so I assume that those are the ones they install, when it comes down to a replacement engine. I have not looked at Jasper's website, if they have one, to see their words.

 

I'm not an expert, but the sense I get is that the cast-iron block will take an enormous amount of abuse before it warps. Of course, you always check it with a precision straight-edge when the heads come off. If the block is warped, it would have to come out to re-surface it (there's no way to resurface it in-situ), and that adds to the cost. Me, if I found a warped block, I would be looking very carefully for cracks in the block.

The heads (aluminum) are another story. But if the heads are flat (there's the straight edge again), there's no point resurfacing them just for fun. On the other hand, if you're having a machine shop do other work (like a valve job), slapping it on the mill to resurface the head with 0.003" doesn't add much (and they sure look pretty!)

I would guess that you'll get another 30-100,000 miles with just the repairs listed by the shops you called. But you have to remember that you're pulling the heads off a 29-year old engine. Everything around the engine is old, brittle, and just itchin' to break. This is not a deal-breaker, just be ready to pay for another half-dozen new parts (TVV, FPR, hoses, ....)

Jasper doesn't sell engines directly. https://www.jasperengines.com/find-a-price I assume you're ruling out DIY. Or, if you're on YotaTech, you might be willing to give it a try. You're certainly no dumber than me, and I've done it. It will take some time, and you'll have to buy some tools that you wouldn't otherwise. The money you save (thousands) when divided by the time it takes won't make you rich. But the satisfaction of doing it yourself is why you're on YotaTech in the first place.

 

It's been over 2 weeks since I had it towed home. Will be having it repaired soon. I won't have the car sitting around for a year without fixing it. I'll either have it repaired or disposed of.

Going back to my 1st question, is it true that Toyota recommends not resurfacing the cylinder heads if the cylinder heads are not warped?

 

Good question (still ). This drove me to my 1989 truck Genuine Toyota Repair Manual, Volume 1. For 1989 3VZ-E; Maximum warpage allowable: 0.0039 for each surface that contacts cylinder block or manifold. If greater, replace the cylinder head. For the block it is 0.0030 inches. If greater, replace the block.The 0.0039 number is same as in my '08 Corolla manual. So Toyota doesn't discuss warped, but still within allowable number. My guess: they assume that the clamping force applied by the fasteners can reliably take up the slack, good enough.

Hmmm that begs a question about "Remanufactured/rebuilt/reconditioned engines."

Good luck on whatever you decide.

The Haynes Manual for '72 thru '94 says heads can be resurfaced, and has a lot of good info. You might call around to the automotive machine shops in your area and ask their opinion too.

 

http://web.archive.org/web/201208130...68cylinder.pdf page EG2-64.

The '94 FSM looks to be the same as JJ'89's 1989 manual. It says nothing about resurfacing; if warpage exceeds 0.039" (0.10mm), replace the head. So I can't say that "Toyota recommends not resurfacing ..." at all.

 

During the recall we replaced A LOT of blocks. But never for warpage. It was solely due to the etching that occurred at the very back where the gasket was prone to fail. If the etching(pitting) was deeper than .010" Toyota said to replace. Sometimes we replaced just the short block, sometimes heads and block. Ironically, the customer who took the worst care of their vehicle and drove the heck out of it while the headgasket was leaking tended to get the most free parts under the recall. Talk about a hail Mary rescue.
The official word from Toyota regarding resurfacing and decking on the 3.0 during the recall was we couldn't take off more than .010" combined, block and heads. If the block and heads were straight with no issue we were instructed to just replace gaskets, no machining. So yes, it's true. This was the first time Toyota had acknowledged machine work while performing warranty/recall repairs(except for possibly rotors/drums), at least to my best recollection. Prior to this, if a component was warped beyond spec. we replaced with new.

Many repair shops are starting to get away from doing headgaskets. I guess the can-of-worms that can arise afterwards has bitten them once to often. So finding shops willing may be getting harder.
Before I'd disassemble any customer's engine, I'd have the tech do a leakdown and compression test on all cylinders and document the results on the repair order. This was actually B.A.R. protocol. This is valuable info to have once it's opened up and you need to make informed choices.
Once the engine was opened up and the failure was determined I prepared estimates for a customer's vehicle. I'd have the one main list that had everything listed and priced that would address the issue and correct the problem. I had a second list that included all the things that would be proper to replace at the same time. Things like v-belts, timing belts, water pump, etc. After the leakdown test is done, but before teardown commences you discuss the potential costs. I just hated blindsiding someone after they were already thousands of dollars into a repair. If you had done enough similar repairs you had a very good idea what was going to come up once things got rolling. Things can still happen, but a good service facility does their best to instruct their customer on the range of possibilities, worst case/best case.

You might want to drain the oil and coolant for now. Pull the plugs and shoot some atf in there and turn the engine over a few times(with plugs out) to coat the walls.