Do I need to worry about all the gunk inside the engine when I put the head back on?
What is the best way to remove it?
Can I just run the engine and changer the coolant and oil a few times?
I have pulled the head and I am getting it resurfaced.
I don’t want to have to pull the block if I don’t need to
The head gasket blew about 3 months ago, I had the car towed home and drained the oil while it was still steaming and it’s been in the garage ever since.
The other thing is that I still cannot find what made the engine overheat in the first place, I have checked the Thermostat and water pump and both are fine, there was no coolant left so I guess it’s just a blown hose somewhere?
Rebuilding KA24E engine after blown head gasket?
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yellow_jacket
- Posts: 1355
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- Car: 95 240sx
could have been a lot of things. Just be very careful not to let it overheat when you start it back up. I have heard some people say that the chain ate through the front cover. More than likely the head blew, you were out of antifreeze, or the thermostat stuck. As far as cleaning the block out, you don't need to. Just take an air gun and blow all of the trash out of the holes for the head bolts and out of the cylinders. You already said you are changing the oil which is a must. Personally, I would change it again after 500 miles. I would also take out the drain plug one more time to make sure it is good and drained. You should have the machine shop check for cracks while they have the head.
You could check your upper and lower radiator hoses, which come directly off of your radiator. There are 2 coolant lines going from the front cover to the intake manifold and 2 more going to the firewall (one from the intake, one return to the engine block).
BigRed: if your headgasket is blown, you will overheat even with a perfectly good water pump, thermostat, radiator and all hoses.
Be sure to tighten the head bolts correctly. You are to tighten them to 62 (if i remember correctly) ft lbs in the correct sequence, then loosen them all, then retighten to 90 (?) then one more quarter turn. This worked fine for me on my engine rebuild, for about 2 days. Then i started overheating. Turns out my head bolts needed tightening down one last time. Since then (3 weeks now), the car has run perfect!
Good luck!
BigRed: if your headgasket is blown, you will overheat even with a perfectly good water pump, thermostat, radiator and all hoses.
Be sure to tighten the head bolts correctly. You are to tighten them to 62 (if i remember correctly) ft lbs in the correct sequence, then loosen them all, then retighten to 90 (?) then one more quarter turn. This worked fine for me on my engine rebuild, for about 2 days. Then i started overheating. Turns out my head bolts needed tightening down one last time. Since then (3 weeks now), the car has run perfect!
Good luck!
Iam in the process of rebuilding my SOHC now, Iam rebuilding the head(valves/seals) I jsut got it hot tanked and everything. Can't wait to hit the bottom end!!! <--sarcasm
Damn I thought parts for imports were cheap!!!! Why the hell is the exhaust valve 7 dollars more expensive then the intake!?!?! Anyways its a fun project for someone that has never done such a thing
Perfect 1st mechinical journey 
Damn I thought parts for imports were cheap!!!! Why the hell is the exhaust valve 7 dollars more expensive then the intake!?!?! Anyways its a fun project for someone that has never done such a thing
Perfect 1st mechinical journey -
yellow_jacket
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- Car: 95 240sx
Like JNM240 said, when you torque the head bolts make sure you do it correctly. The sequence and the proper torque specs are sooooo important. So make sure you have a good torque wrench(accurate).
As far as hoses leaking, if you can't see antifreeze leaking on your driveway, your hoses are probably not leaking any significant amount. So just run it in your driveway and let it warm up.
One more thing, it is extremely important that the threads in the head and the head bolts themselves are clean or they will not torque properly.
As far as hoses leaking, if you can't see antifreeze leaking on your driveway, your hoses are probably not leaking any significant amount. So just run it in your driveway and let it warm up.
One more thing, it is extremely important that the threads in the head and the head bolts themselves are clean or they will not torque properly.
Thanks guy's.
I have the $120.00 Nissan shop book so I have all the specs needed.
JNM240: I am getting a new head gasket, in fact I'll just go ahead and replace all the gaskets while the engine is sitting in bit's all over my garage.
Yellow Jacket: drain plug has been sitting in the ashtray for 3 months and I will change the oil a few times at 500 miles, thanks for the hose tip!, btw: no damage to front cover, water pump is OK and thermostat is operational and within operating range, I guess I'll just have to look for a busted hose now.
Good tip: Buy a pack of paper coffee cups and a marker and masking tape, mark the cup with the engine piece you are removing and put the bolt's, nut's, clip's in the cup.use masking tape on each hose or harness you remove and mark the tape in numbered pairs (1&1, 2&2 etc)
I have the $120.00 Nissan shop book so I have all the specs needed.
JNM240: I am getting a new head gasket, in fact I'll just go ahead and replace all the gaskets while the engine is sitting in bit's all over my garage.
Yellow Jacket: drain plug has been sitting in the ashtray for 3 months and I will change the oil a few times at 500 miles, thanks for the hose tip!, btw: no damage to front cover, water pump is OK and thermostat is operational and within operating range, I guess I'll just have to look for a busted hose now.
Good tip: Buy a pack of paper coffee cups and a marker and masking tape, mark the cup with the engine piece you are removing and put the bolt's, nut's, clip's in the cup.use masking tape on each hose or harness you remove and mark the tape in numbered pairs (1&1, 2&2 etc)
I am in the process of rebuilding my engine on my 89 240. And I had the same thing. Overheating and didn't know why. Took the head in and they told me it was warped, need to check my cam and get a valve job. But since I decided to go through the entire block I have found out that three out of four cylinders had real low compression, due to the rings overheating. So you might want to tear you entire engine apart and go through it, just to be on the safe side.
Thanks for the input crave209.
We have an '89 and a '90, I take real good care of them and always check out stuff that does not look or sound right, that includes keeping an eye on the temp gauge but unfortunately these cars have no idiot lights for overheating so I didn't notice a raise in temperature, in fact I only noticed the engine stuttering when exiting the freeway and when I looked at the gauge it was reading "COLD," my best guess is there was a catastrophic failure with the coolant system (radiator or hose) in which all the coolant was lost in a short time and the coolant level fell below the temperature sensor before it had a chance to even heat up.
The cylinder walls look fine (no scoring) and the bottom end is flat (less than 0.01mm from true), the only damage I can see the head is warped 0.01mm, it was probably warped more than that while it was cooking as the #7 head bolt was loose.
The engine was still running OK when it had a chance to cool down and I had it towed home so I doubt there is too much internal damage.
We have an '89 and a '90, I take real good care of them and always check out stuff that does not look or sound right, that includes keeping an eye on the temp gauge but unfortunately these cars have no idiot lights for overheating so I didn't notice a raise in temperature, in fact I only noticed the engine stuttering when exiting the freeway and when I looked at the gauge it was reading "COLD," my best guess is there was a catastrophic failure with the coolant system (radiator or hose) in which all the coolant was lost in a short time and the coolant level fell below the temperature sensor before it had a chance to even heat up.
The cylinder walls look fine (no scoring) and the bottom end is flat (less than 0.01mm from true), the only damage I can see the head is warped 0.01mm, it was probably warped more than that while it was cooking as the #7 head bolt was loose.
The engine was still running OK when it had a chance to cool down and I had it towed home so I doubt there is too much internal damage.
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yellow_jacket
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Oatmealman
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yellow_jacket
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A valve job is not just cleaning the valves or the head off. It is actually resurfacing the head surface and the valve surface so that they meet correctly and have a good seal.
Of course once the valves are sealing like new again the compression comes back up. Normally this would be good, but with an older motor the rings can't always handle the increased compression and you will get blow-by. And valve jobs(if you just give them the head with valves and springs still in place) usually costs about an extra 400 on most imports
I usually spend about 550-700 per car to get heads resurfaced, checked for cracks, valve job, and the gasket set.
Of course once the valves are sealing like new again the compression comes back up. Normally this would be good, but with an older motor the rings can't always handle the increased compression and you will get blow-by. And valve jobs(if you just give them the head with valves and springs still in place) usually costs about an extra 400 on most imports
I usually spend about 550-700 per car to get heads resurfaced, checked for cracks, valve job, and the gasket set.
I'm paying only $60.00 for the head shave or $200 for both shave and valve grind.
Would you not get the same blow-by by running the engine hard, you are after all just asking the car for more power and in doing so creating more pressure inside the cylinder?
It would be good for gas milage and since it's my wifes car she never takes it above 4,000 rpm.
Would you not get the same blow-by by running the engine hard, you are after all just asking the car for more power and in doing so creating more pressure inside the cylinder?
It would be good for gas milage and since it's my wifes car she never takes it above 4,000 rpm.
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yellow_jacket
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TrunkMonkey
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not true.yellow_jacket wrote:Of course once the valves are sealing like new again the compression comes back up. Normally this would be good, but with an older motor the rings can't always handle the increased compression and you will get blow-by.
just because you have an older engine doesn't mean a simple vale job is going to cause blow by. it has to do with how well the engine has been maintained. my 89 had over 200K miles on it and still had 170 psi on all 4 cylinders. it burned no oil whatever. i would have done a valve job in a heartbeat.
only if your engine is in poor condition is a valve job not recommended. if your already burning oil and have poor compression, there's no need to make matters worse.
-demetrius
I have 150K on this car and the compression is as good as my car which has 197K, I had a compression test done on mine and all were within 4 PSI of each other.
Like I said I take real good care of all my cars, change the oil every 3,000 miles (5,000 in the Camaro sine that uses synthetic and revs much lower) and I have never lost more than 1/2 quart between oil changes.
Like I said I take real good care of all my cars, change the oil every 3,000 miles (5,000 in the Camaro sine that uses synthetic and revs much lower) and I have never lost more than 1/2 quart between oil changes.
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yellow_jacket
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I'm sorry if I wasn't more specific. You are right, only problem is that by the time most shops get your car the head is already blown and if you run a compression test with a blown head you obviously will not know the condition of every cylinder. But if you have checked your compression recently then that would definetely work.
You know that's a good point!
I wonder how many people have junked their cars because the mechanic told them the compression was shot.
BTW: I dropped the head off this morning and Toby (real nice Jamacan guy) told me that maby 1 out of every 100 KA24E heads he machines will have cracks in it which means that these heads are very strong, the weakest? Ford V6 and 4.0 V8, & Chevrolet's LS1 & LS6 heads!
Yikes, but he told me to remember that if the LS1 overheats it will alternate firing banks and run on half power enough to get you to a shop, he also reminded me that if I blow a head on the Camaro I could always go for a set of 450 HP ARE heads :-)
I wonder how many people have junked their cars because the mechanic told them the compression was shot.
BTW: I dropped the head off this morning and Toby (real nice Jamacan guy) told me that maby 1 out of every 100 KA24E heads he machines will have cracks in it which means that these heads are very strong, the weakest? Ford V6 and 4.0 V8, & Chevrolet's LS1 & LS6 heads!
Yikes, but he told me to remember that if the LS1 overheats it will alternate firing banks and run on half power enough to get you to a shop, he also reminded me that if I blow a head on the Camaro I could always go for a set of 450 HP ARE heads :-)
here is the head bolt retighting sequence and torque specs from the top, left to right 9,3,1,6,8 then 7,5,2,4,10 this is the order you should use, also use this 5 step when torqueing, torque all bolts to 22 ft.lbs then 58 ft.lbs loosen all bolts then torque to22 ft.lbs then lastly torque bolts to 54-61 ft.lbs hope this helps
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ShadowKnight006
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Does anyone know how many hours approx are involved in rebuilding a ka24e? I just bought one that has 122K, very clean, but I was thinking of having it rebuilt down the road. I was thinking of buying a topline kit from importperformanceparts.com then having a shop do the work( I am not to mechanically enclined(spelling) yet).