Can I Fix Blown Head Gasket

toyota
rav4

#1

My car has a blown head gasket. The shop wants more to repair it than the car cost me. I’m thinking of doing the repairs myself. Am I nuts? How hard would this be for a novice?


#2

It’s not something I would try to do myself.

Have you tried taking it to another shop for another quote? This may be a sign you need to let the car go, or drive it into the ground. Good luck.


#3

Depends on how “novice” you are, if you have a place to work on it, have a buddy that can drive you back and forth to the parts stores and how many tools you have access to or are willing to buy to get the job done. All DIY’ers had to start somewhere on some project and we all had a “first time” for any task we’ve done (I’m still doing first times on various things)

A head gasket can be a bit daunting to the novice especially the timing chain (or belt). Getting it properly re-installed on some cars can be a bit of a challenge. I’d hit YouTube and see if anybody has videoed their head gasket change or head removal on a Rav 4 or similar Toyota and then you can get a good feel for whether or not you can handle the job yourself.


#4

As I was reading up on head gasket repairing I can across comments about using Blue Devil or Bars Head Gasket Fix kits. It almost seems too good to be true. Has anyone ever tried these? Do they really work?


#5

I would only do Bar’s, Blue Devil or any other “miracle in a can” products if I wasn’t going to keep the car very long. Yeah, they DO work, sometimes. It is a band-aid that can fix a leaky head gasket for a while if it isn’t too bad in the first place. If you are thinking of trying it so you can do a head gasket later, I wouldn’t recommend it. It makes a mess inside your cooling system and can clog your radiator over time. If this is a “fix it or junk it” decision, by all means give it a try. My favorite is Bar’s.


#6

I don’t see this as a reason by itself to discard a car.
Is the rest of the car in good shape? Consider the cost and time to get a replacement.
Suppose someone gifted you a nice car.
Would you scrap it if it needed a $100 repair, since that’s more than it cost you?


#7

Is this a 4-cylinder?
How much mechanical experience do you have?
How vast a tool assortment do you own?
Have you got a Factory Shop Manual?
Is there any room under the hood of that thing or is it cramped?
When you look at the steps listed in the manual, does it all make sense to you and seem to be straight-forward?

There are many, many, variables.

I am a novice, but I have lots of nice tools and some mechanical experience. I have put head gaskets on 4-cylinders before. I own Factory Service Manuals for all my cars. I have also bought and made a couple of “Special Tools” to make the job go right / possible.

Also, while doing the head gasket(s) other items should be upgraded while you are working on it. Do you know what that entails?
CSA


#8

Ordinarily I’d say a head gasket is more advanced than a first attempt at home wrenching. You will almost certainly need to borrow tools. Depending on how buff you are, you might need a friend to help you lift the head off and back on. It would be great if that friend were someone who has done car work before.

You will need a torque wrench - a Harbor Freight one will do fine so that won’t cost you too much money. That and a “mechanics tool kit” from somewhere like Costco should give you enough tools to do the whole job.

I would get the factory service manual, and I would also take a picture every time I took something off the engine. You’re going to be taking a lot off to drill down to the head gasket, and it will really suck if you button everything back up and then find that you forgot to put a part on an hour ago. Feel free to have a notebook handy, and take copious notes of what you’re doing as you’re disassembling - then you can refer to them as you’re reassembling.

If you have any questions, stop what you’re doing and ask. Plan on the job taking a lot longer than anyone says it will - those time estimates are based on assuming the person doing the job has done it before. You’ll want a backup vehicle for parts runs and to get to work.


#9

The first engine I ever rebuilt was a SBF. I had a short printed book with some pictures. I did not have anyone holding my hand and this was before the abundance of youtube warriors out there willing to help the DIYer. That engine is still going strong and it liberated me from the need to utilize a mechanic again. I have since built dozens of engines from race car engines, 4 bangers, tractors, lawnmowers, motorcycles, gasoline, propane, and diesel. I am now only limited by my free time. If you have a car that is essentially headed for the scrap pile if you don’t fix it, then this is the perfect car for you to learn on.

To help, first clean the engine. next take pictures of how the parts were arranged before you removed them. Take a box of ziplock bags and a marker and “bag and tag” you bolts and parts you removed. Arrange them on the table or floor in the order than you removed them so you can simply go in reverse order. Use some painters tape or masking tape and label each wire that you disconnect. take your time and don’t force something off. If it doesn’t come off easy, it is likely that you did not remove all the bolts. Don’t over torque bolts during reassemble. Some things could be incredibly frustrating (bolts difficult to get to, bolts stuck and break off). If you have the problem chances are many others have already had the same problem and the internet will help you find a solution.


#10

Do I suffer from short-term memory loss? I don’t know. I can’t remember.

Should I be afraid to ask? I don’t know if I don’t remember what SBF is or if I never knew, but what is it, please?

I did head gaskets on ICE (internal combustion engines), SOHC (single over-head cam) & DOHC (dual over-head cam), but I’m not sure about the old SBF…
CSA :confused:


#11

Small block Ford, I would guess.


#12

Small Block Ford. I got a free engine from a friend that locked up. I tore it apart and sent parts off to machine shop and bought some aftermarket parts and reassembled and swapped it out during winter break.

The locked up engine came from a local rebuild shop. The oil pump driver sheared off and wrist pen froze up. The engine had less than 10 miles from the rebuild shop. The assemble lube was still covered on the mains, rods, and cam.


#13

It took me a few minutes but that is what I figured out.


#14

My first repair on a car was when I was 16, it was a flathead 6 in a Fraser. I had borrowed tools, a putty knife instead of a gasket scraper. and a Motors repair manual. A friend of my stepfather brought over a torque wrench. Those old flatheads were a lot easier to do, but I have done others since. Never did one with fuel injection.

If you have enough patience, there is no reason you can’t do it. You have nothing to lose. Right now your car is broken and not worth fixing.

It might be easier to take off the exhaust manifold with the head, that way you won’t have to deal with heat frozen manifold bolts.


#15

As long as you have the strength and flexibility necessary to ratchet the bolts holding the head onto the block, there’s no reason why this couldn’t be a diy’er job. An engine is constructed like a layer cake, with frosting between the layers, and what you want to do conceptuallly is just remove the top layer from the bottom layer, put in some new frosting, and put the top layer back on.

$$- and time-wise, as a novice diy’er, expect this job will take quite a bit of your time. Figure a 5 days full time effort, 40 hours or your own personal effort or so. An experienced shop tech could probably do the job in 1/4 that amount of time. The reason is that they already have all the tools on hand and have done the same job many times before. But that time comparison diy’er vs pro is no reason for you not to do it yourself. It will just take you a little longer is all. If you have the time to do the job, won’t be a position where you’ll have to rush things, besides renewing your head gasket, it will be a good learning experience. You’ll be able to build on what you learn and do a lot more diy’er fixing, so figure the future cost savings into the equation too.

As far as what’s involved, for an engine like what many Rav 4’s use, the 4-banger 1az-fe, there’s probably about 20 individual steps to remove the cylinder head, and the same number to put it back on again. Plus however many steps are involved in replacing the gasket itself. Most shops wouldn’t just replace the gasket, they’d send the head out to a machine shop to make sure it is perfectly flat, and the macine shop would also do a visual inspection of the valve situation, to see if it might be a good idea to do a full valve job on the head, or replace the valve guides and/or their seals. I’d recommend this machine shop step for your engine too, especially if your engine has ever overheated. Not an uncommon thing for engines with head gasket problems.

If you decide to go for it, don’t try to re-invent the wheel. Get Toyota’s written procedure, then all you have to do is follow it step by step. If you get to te point where you need a special tool, stop what you are doing and go get the tool. Don’t try to do it using mickey mouse methods, that’s how diy’er get themselves into $$-consuming trouble. Best of luck there OP, be sure to let us know the result!


#16

The first thing I would ask a novice when attempting a head gasket replacement is, do you have access to a precision straight edge?

A precision straight edge is used to check the flatness of the head once it’s removed from the block. And depending on the results of the measurements dictates if the head needs to be milled at machine shop before reinstalling it.

So, if you don’t have access to a precision straight edge, don’t attempt this repair.

Tester


#17

Was the engine severely overheating or being driven in this condition for a while? If so, this can damage the rings and cylinder walls along with the engine lower end if engine coolant has contaminated the motor oil.

This can make a head gasket replacement a waste of time and money.


#18

This is a large order if you have no prior experience with auto repair but if you have no alternative, at the minimum you will know more even if the car ends up being scrapped. In addition, to labeling wires, make notes and sketches of where the wires were attached. Bagging and labeling the bolts is essential; don’t think: “I’ll remember where they came from”. It does not work well!

If your OHC head gasket failed due to a warped head, do not mill the head if it is more than about .003" out of flat. You will either need a new head or will need to find a shop that can heat the warped aluminum head and press it back into flatness. Otherwise your cam bearings will be misaligned and the cam bearing surfaces in the head can wear quickly. If your engine is OHV, then mill it flat with no worries.

Do you know if the head gasket failed or did the head crack to make a combustion leak into the coolant system? If the latter, then a new gasket will be a waste of your money and time. Carefully inspect the old gasket and head surfaces and if no evidence of a leak then you need your head pressure tested or else just buy a new head. Aluminum heads can crack so a used head might be well on its way to being cracked. A head crack might be repairable if you can find it.

I recently replaced a head and gasket on a VW and did not at all enjoy the task. It’s a dirty, time consuming task and I dread ever doing it again. I even had a head start already (so to speak) knowing how to replace the timing belt and tensioner. Like you, I had to do it or just had a car that needed to be scrapped. If your back does not like bending over for long, forget about repairing the car.


#19

I think the answer is pretty simple. If you have to ask us if an inexperienced person like you can do this job, then the answer is definitely “no”.

You’ll know if you can do it, because you will have done other jobs that were new to you, and got them done anyway. Most of us learned these skills by being overly confident and just plunging in, or by being so broke that there was no choice and the car was already broken.