4Y and disposable head gaskets

[Willied]

So after the weekend I have to replace the 4th head gasket on the 4Y in the last 45000km's.. Does it ever end or was the 4Y sent by the Devil to torture us!! :evil:

Recent history of the motor: Fuel rail pressure regulator went after doing 3000km on EFI and as a result the motor cooked and I had it completely rebuilt. Added some horses and have to say the motor was very lively and after doing 1500km it just popped a gasket again.

What do I replace it with.. does anybody have any information for some performance parts that can handle 10:1 compression in the 4Y or maybe contact information to have a copper gasket replacement fitted to lower pressure to 9:1 and just get some reliability from the motor as I have a Friday lemon dubbed "Staan en Breek" by the family.

[Mud Dog]

Is this an original Toyota 4Y or a Chinese copy? Firstly ensure that the block is not compromised on the head face (corrosion), if so, a light skim might be required. Nine times out of ten it will be the head itself which may be warped or corroded. Replace the head with a thicker gasket to reduce the compression a little Copper gaskets can be made up for this. Also replace the head bolts since they may be stretch bolts and should not be re-used. Torque to spec (cannot remember, but I think it was somewhere around 52nm ... you would have to check). Very important is to re-torque after 1000kms, and when you re-torque first slack off each bolt by a quarter turn and re-torque before moving on to the next.

[JohanM]

Willie,

Dit wil vir my klink asof daar n onderliggende probleem is wat veroorsaak dat die gasket bly blaas. Dinge waarna gekyk moet word is of die head geretorque word en dan omdat die head so baie al afgehaal is sal ek die headboude almal vervang met nuwe boude van Toyota. Behoort so 25 per bout te kos. Ook die gasket self moet net OE toyoa gasket wees of as die anders moet, dan n payen gasket. Die kompressie op die enjin sal nie maak dat die gasket net so blaas nie. Ek self ry n non standard efi 4y enjin en ek het sover nog nie probleme met herhaalde gaskets gehad nie.

Headgasket failures is gewoonlik related aan hitte probleme,foutiewe instalasie, swak onderdele, swak vakmanskap en ook dan ouderdom wat gewoonlik die minste voorkom.

[Willied]

Herewith an idea about what state the motor was in before the last gasket replacement. The head was cut straight and the block was cleaned off as well. All the bolts were replaced and according to the shop doing the rebuild a re-torque wasn't required but will include this into the next replacement.

So Toyota is best you say, it just seems cheap vs some of the replacement parts.

Vir hitte probleme en die like, ek het al 'n 3 core alum radiator in wat die engin baie gelukkig hou en die temp het eers begin optel nadat die radiator leeg geraak het. Maar ek oorweeg om biedjie meer verkoeling by te sit vir harde werk in sand en in die veld.

[Willied]

Okay, nou die man se instruksies deur gelees en hy moes wel geretorque word.. so ja.. in die *a*.. Nie gedink hy sal so naby aan 'n 1000km so maak nie.. Maar hy was nie warm nie en glo nie dit sal nodig wees om hom weer reguit te laat sny nie. Sal hom maar die week strip en kyk wat gebeur het.. Silinder 4 is wel intermittent.. Loop met 'n leke mis.

[Mud Dog]

As hy die gasket blaas is dit gewoonlik tussen nr4 en 3 of tussen nr4 en die water jacket. Die 'vleis' is maar min in daai omgewinge, en nr4 is die verste van die verkoeler af, so hy sal die warmste word.

[AM Racing]

When overhauling a motor we replace the water pump and thermostat as well. The cylinder head must be retorqued after 1000km or so and it must be done cold.

[Willied]

Andy, ek dink dit is die keer op die water jacket by no 4. 4 is dood vir 'n start en dink die head stoom in die silinder in. Was laas op no 2 gewees so dis darem nie elke keer op dieselfde plek nie. Sal maar 'n sample van die water vat en vir gas laat toets anders kan dit 'n dooie plug ook wees wat vir no 4 dood maak.

Dylan, Thank you.. Last time I did retorque it at 1000km and it lasted good. Will simply replace the gasket and retorque it at 1000km as it needs doing. Pump was still in good condition and the thermostat was replaced. Will look for a lower temp setting thermostat to have it open sooner to allow for a cooler running head.

[Mud Dog]

The standard thermostat should be more than adequate as long as the pump, radiator and visco fan are in good working order.

[JohanM]

The standard thermostat should be more than adequate as long as the pump, radiator and visco fan are in good working order.

Willie like Andy mentioned here, the cooling system should be able to handle the normal heat generated by the engine.

Andy, ek dink dit is die keer op die water jacket by no 4. 4 is dood vir 'n start en dink die head stoom in die silinder in. Was laas op no 2 gewees so dis darem nie elke keer op dieselfde plek nie. Sal maar 'n sample van die water vat en vir gas laat toets anders kan dit 'n dooie plug ook wees wat vir no 4 dood maak.

Dylan, Thank you.. Last time I did retorque it at 1000km and it lasted good. Will simply replace the gasket and retorque it at 1000km as it needs doing. Pump was still in good condition and the thermostat was replaced. Will look for a lower temp setting thermostat to have it open sooner to allow for a cooler running head.

Willie remember that with a engine the cylinderhead like the cooling system and the combustion chambers, needs to run within a certain specified temperature range to ensure that it working optimum. With having a 3 core radiator I am suspecting that your viscous fan might not be doing its function the way it should be, thus having to add more cooling capacity to prevent it from overheating. Also by doing this, you can cause the thermostat to malfunction due to having to open but not being able to due to having to much cold coolant on the one side and warm water on the other side of it.

Remember that the water flow bypasses the thermostat when it is closed and to assist the heater radiator circuit to warm up faster to be able to warm the cab within a short distance of driving in cold conditions. Thus the waterflow is still being circulated partially through the engine and the water pump is recirculating the water through the radiator but not effectively cooling it as its flow is restricted due to the thermostat being closed or not opening properly.

Thus as the engine warms up I have noticed that with a sticky thermostat (not opening correct or shutting to quickly) and an uprated radiator it will not always overheat, but can cause hot spots in the engine which can also lead to head gasket failures as explained above.

Hope this helps you also in understanding the failures that happen and what can possibly contribute towards it.

[Willied]

Remember that the water flow bypasses the thermostat when it is closed and to assist the heater radiator circuit to warm up faster to be able to warm the cab within a short distance of driving in cold conditions. Thus the waterflow is still being circulated partially through the engine and the water pump is recirculating the water through the radiator but not effectively cooling it as its flow is restricted due to the thermostat being closed or not opening properly.

Thus as the engine warms up I have noticed that with a sticky thermostat (not opening correct or shutting to quickly) and an uprated radiator it will not always overheat, but can cause hot spots in the engine which can also lead to head gasket failures as explained above.

This might explain why the radiator was cool even under load and the motor war hotter than normal. So the radiator might have kept the thermostat to cold to open properly and contributed to the situation. Short of slotting the crappy old radiator back, how can I prevent this from happening in future?

[LouisZ]

Head Boute!!!

Nuwes altyd as jy na die 2de keer strip. Na 1000km Torque na 78N/m.

Dan ook kyk BAIE mooi na die Gasket, Daai gate vir die waterchannels is nogals klein en blok , ek gebruik 'n Dremel om die te vergroot, sny die stuk versigtig uit tussen die 2 gatjies per channel.

Groette,
Louis

[JohanM]

Willie,

It is quite possible that it could have been the culprit that have caused all the problems.

I will recommend that you consider getting a replacement alu radiator for the SFA 4Y from Silvertons radiator. Should be roughtly about 1K. Also I will advise you to consider replacing the viscous coupling on your fan, but buy a OE part from Toyota not any generic part of chinese cheapie. Part from Toyota is 2.5K but this will allow the engine to reach normal operating temperatureand bear in mind that the fan is only needed to keep the temperature constant when airflow is reduced due to slow driving or when experiencing high ambient temperatures and/or high load conditions.

Bear in Mind that the Alu radiator compared to standard copper is roughly about 30% more effecient in dissipating heat, thus the Standard size alu radiator should be plenty to keep the engine normal, unless the airflow is highly restricted to the radiator by oversized spots, winch badly positioned, grass nets ect, as these will contribute to overheating in any cooling system.

[Willied]

Thanks guys, off to the indy I go.. Will have him take a look and let you know which route I take.. Except for the hassle of having it done yearly it is atleast cheap..

[Willied]

Okay so the motor when in yesterday and had a look at it today, no warping on the head but it is very thin and the guys are worried about another skim.. Will clean it off and measure it to see how straight it is. If needed a copper gasket will make up the difference.

Both water jackets next to cylinder 4 had gone and pushed water into the cylinder. Seems like the gasket had a weak spot. It is being replaced with a Payen set.

Will be loading the bakkie with a ton and make it work so if the problem persists it will show real soon.

[4 runner oldie]

Just wondering Willie did you ever try a New Head . Just saying so cause my gasket blew many times like you too . Head and rest checked everytime but .

[Willied]

Just wondering Willie did you ever try a New Head . Just saying so cause my gasket blew many times like you too . Head and rest checked everytime but .

The head is a custom job that cost me a packet, decided that this is the last opportunity the 4Y will get. Did a costing and it will be to expensive to put something else in there after what I spent. So if it goes I will drop a standard head in there and get it running well and then flog it. The Hilux and Isuzu will then be dropped on the retail of a 4.2L Diesel Cruiser.

[X-Dors]

Willie
net so verintresantheid n vriend van my se 4 y gasket het ook nou gegaan op 1250km na dat die motor heel gedoen is , maar hulle het hom ook nie getorque nie .En my 22r se water het weg geraak weens top maar my blok het ook getrek van die hitte so kyk of die nie dalk getrek het nie , dit kan ook die probleem wees .

[Willied]

Willie
net so verintresantheid n vriend van my se 4 y gasket het ook nou gegaan op 1250km na dat die motor heel gedoen is , maar hulle het hom ook nie getorque nie .En my 22r se water het weg geraak weens top maar my blok het ook getrek van die hitte so kyk of die nie dalk getrek het nie , dit kan ook die probleem wees .

Met die oorbou is die blok deur gegaan en was nog 100%, die laaste episode het die engin nie so warm geword dat die blok kon seerkry nie. Dink dit was maar net 'n foutiewe gasket gewees. Retorque is 'n moeilike ding, daar is baie meenings en baie ouens kan dit staaf met ondervinding. Ek het eenvoudig 'n Vrydag bakkie en sodra alles in tip top shape is sal ek hom vir 'n nuwe eienaar gee wat nooit sal fout hê met hom nie.. Is mos maar hoe die lewe loop.