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Toyota Service
Toyota Service, Toyota Expert
Category: Toyota
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1998 Toyota RAV4 won't start. Head gasket replaced

Customer Question

I replaced a head gasket on my 1998 Toyota RAV4. Car will not start.
Submitted: 1 year ago.
Category: Toyota
Expert:  Kevin replied 1 year ago.

Does engine turn over?

Customer: replied 1 year ago.
It cranks over but will not start. No spark.
I replaced the cylinder head because I had a broken valve. So I installed new gasket with a good like new head. And that went on good by the book.
Expert:  Kevin replied 1 year ago.

So all earths and crank sensor are connected correctly after head refitted?

Customer: replied 1 year ago.
Everything should be good. But I'm wondering about the cams being lined up and the timing with tdc. I need to pull the valve cover off to look at the timing marks.
When I go to start the car, I get no spark. I pulled out all the plugs and reconnected to the wires and started the car in a dark garage and saw no sparks. Also I did a compression test and I got 90psi on each cylinder. Maybe the valve train is off?
Expert:  Kevin replied 1 year ago.

Possibly the car may be preventing spark if timing is that far out but I find this unlikely . Double check your timing first for peace of mind do you know if you have fuel pressure ?

Customer: replied 1 year ago.
I have fuel pressure.
Expert:  Kevin replied 1 year ago.

Ok double check timing and then I would go back and double check connections on sensors and crank sensor also ignition coil then double check earths . It has to be one of these as car ran before

Customer: replied 1 year ago.
90 psi on each cylinder. With no spark. He cam hole lines up with the mark and the crank v notch on tdc. Could it be possible that I lined up the intake and exhaust shaft cams wrong. Maybe the camshaft sensor and the crankshaft sensor not sending the right info to the computer since not turning properly with each other
Expert:  Kevin replied 1 year ago.

This sounds correct I would be double checking the other items I listed

Customer: replied 1 year ago.
Shouldn't I get more then 90 psi and also this? I had some fuel,leak also. After starting just a few drips. I've done fuel rails before on other cars similar motor, injectors, etc. if I'm flooding the engine, no spark, is there somewhere the fuel can leak to? Like we hole or out intake manifold. Legal seems to be coming back out on the side near the firewall. Can't tell where it's coming from?
And I know I installed and torqued the head gasket properly.
Expert:  Toyota Service replied 1 year ago.

Let me verify that you have 90 psi compression on all of the cylinders.

Customer: replied 1 year ago.
I have good compression from 125-140 on all cylinders. Car when starts and runs is very smokey. I have oil on all the plugs. #3 was the first to trip misfire. ran it last night. this morning is when it tripped the code.
2) oil is seeping out of the exhaust. not leaking from the head/exhaust area gasket but its the next separation in the exhaust where the 2 bolts and other flange is seeping. Chemical block test from radiator was good. All blue, did it a few times.
Expert:  Toyota Service replied 1 year ago.

This sounds initially like you have a broken, seized or otherwise compromised oil control rings on the pistons. However, before we discuss rings, there are bigger issues here. There is the possibility that you have the head gasket on backwards. Are you sure you placed it properly? Oil dripping out of the exhaust indicates an extreme amount of oil. Much more than broken oil control rings would cause. Good compression indicates no cracks in the pistons. Another reason is bad valve guides, or forgotten valve seals on the valve stems. Were these replaced when you fitted the new gasket? At least valve seals? You should always replace valve seals when the head is off. If this engine was in my shop, I would be taking a good long look at the valve seals before anything else.

Customer: replied 1 year ago.
I'm sure i put in the gasket correctly. it was an MLS like the one i had before. i used a torque wrench from AutoZone that i didn't really think was a good idea. but i followed the torque procedures. tighten then 36ft then 90degrees. the head i got from a pick yar that recently came in. it came out of a practically brand new rav4. the head looked like it came out of factory. but no i didn't changed the valve seals. the reason i replaced the head was because of a #3 cracked exhaust valve. the smoke that came out of the head with the #3 cracked valve and the smoke coming out of this head is the same. only, the cracked valve had 0 compression while i got good compression on this head. now on this head... maybe the torque was not right? because I'm thinking why oil on all the plugs. but yeah bad ring also crossed my mind as well as being mad at not changing the valve seals.
Expert:  Toyota Service replied 1 year ago.

If the torque was not right, you would have compression spraying out from between the head and the block. An oil leak would be sprayed out instead of being sucked into the engine and coming out the tailpipe because you have 120 PSI of compression pressure (lots) and only 14.7 PSI of intake pressure (this is the atmospheric pressure/very little). Note that if the valve seals are bad, engine oil is sucked into the intake down the valve guides that puts oil on the plugs.

Customer: replied 1 year ago.
would bad valve seals make that much smoke? I've had the same ravs before but just that puff that comes out in the morning. this smoke is almost like a smoke screen. i noticed last couple times at idle it wasn't embarrassing bad and i let that idle for a while. then i stepped on the gas and it got bad.
Expert:  Toyota Service replied 1 year ago.

Assuming that the PCV is not sucking wet oil out of the top of the valve cover, seals can and will give you a tone of smoke.

Customer: replied 1 year ago.
would seals also cause oil leak in exhaust manifold? I've never seen oil leak in e.m. Coolant temp is good.
Expert:  Toyota Service replied 1 year ago.

Whatever oil is not burned up in the combustion process will be pumps into the exhaust manifold.

Customer: replied 1 year ago.
oil can be coming down the intake valve, the exhaust valve and exiting exhaust?
Expert:  Toyota Service replied 1 year ago.

Absolutely. The action of the piston going down can draw the oil down the stem and then push it out he exhaust

Customer: replied 1 year ago.
is at-205 worth a shot? any experience with that? just curious and wouldn't mind to see what it does. but also I've never done the rope trick for valves. it'll work?
Expert:  Toyota Service replied 1 year ago.

AT-205 might be worth a shot, assuming the seals are not cracked or really worn out. I would try it.

Customer: replied 1 year ago.
any other tricks? i disconnected the pcv from throttle side while car was running and car was surging. i also removed oil cap while car running was running to feel air psi. and also put some paper near exhaust pipe and it fluttered but not as bad as i had when i had a cracked #3 exhaust valve. this stuff mean anything or help you?
Expert:  Toyota Service replied 1 year ago.

Check to see if the inside of the PVC tube is wet with oil.

Customer: replied 1 year ago.
what would that mean? what makes you think of that?
Expert:  Toyota Service replied 1 year ago.

That would mean that these is something wrong with the valve cover, or the cam oil is not draining back to the pan thru the drain tubes. This will cause the PCV to suck wet oil out of the PCV fitting

Customer: replied 1 year ago.
I did a compression tes again this morning. Let the car warm up and this time I had the gauge in view as I sat down in the car with foot on gas. It took about 10 " vizz-vizz etc " and I cranked until I got the highest reading. It was about 180 on each. But oil were on the plugs when I took out cleaned and put back in couple times. Very oily. And yes, some drops from the exhaust pipe and probably got a pinhole about 2 feet away from cat cuz it's seeping out of there Also. So looks like new head gasket is good? Installed good? But probably rings or stem valve seals? I also checked pcv and that's good. Um also if it is either valve seals or piston rings is there a way to know? I know about leak test but isn't there a trick or something to check for?
Expert:  Toyota Service replied 1 year ago.

If you have good compression, that tells us we have good compression rings and no cracks in the top of the piston. That does nto tell us if we have a scored cylinder though. A bore-scope would tell that for us, but not a lot of people own one. As long as it has good compression, we can assume the head gasket is tight. I am thinking valve seals. There is not test for them; this is a visual inspection. There is a leak test for cylinder head gasket issues..There is a tool that screws into the spark plug socket. The engine is rotated so the valves are closed. Shop/compressed air is then let into the cylinder. If air bubbles out of the radiator fill area, the head gasket is leaking. I would assume that is air was shooting out of the oil dipstick or PCV position, we could cay we have a serious cylinder scoring issue. I still think valve guides and seals though.