cooling system

[dmann1]

I needs some help. I have an 05 400z. long story bought used. out riding in the sand and it seemed to be running hot check overflow bottle and found it at the full mark but checked the radiator and it was empty.so i put new coolant and t stat and new hoses on. Now when i ride the cooling system has so much press it blow coolant out the radiator cap. I thought the head gskt was blown so i put one in. it actually looked like the head gskt wasn't sealing all the way around the cyl. now i have it back together and it stiil blow coolant out radiator cap. this really blows:( please help please if you may have seen this or know what going on sorry for the long story.

[cataway]

there are some things to check is the water pump working i have heard of the teeth braking off the drive gears hence no water flow , there is a thermostat is it opening , is the fan coming on what TQ did give the head bolts ?

[dmann1]

the fan does come on and goes off like normal, it seems. the torq on the head bolts i set at 35 ft lb. I didn't check the water pump but the dealer just did the side cover recall and they didn't say anything about the water pump being bad but who knows I guess its something to look at?

[dmann1]

so i just pulled the side coverto check the water pump the drive gear looks great and the impellar also looks good don't think its my water pump. just curious when i replaced the head gstk i didn't replace the lower gskt between the cyl and the case could i be getting pressure from that gskt being blown does'nt quite make sense but maybe I dont know its frusterating:grr:

[stichy85]

find some sort of rubber stopper or something to make like a cork in place of your radiator cap. drill a hole in it just big enough to run a hose through it to go into the radaitor but make sure the hose seals off good . put it in place of radiator cap and run the hose into a clear bottle of water. run the engine and if it blows bubbles in the bottle of water you are getting combustion into the cooling system somehow

[Limited Z_400]

did you check the head surface for warpage?

[dmann1]

i took the head off again tonite i will check the head surface for warpage tomarrow at work. i'm thinking that is may concern or maybe a crack i will let you know what i find out tomarrow. thanks for all the suggestions.

[fmftrx300ex]

maybe you have a bad radiator cap why wouldnt u check that if your fan pump and head gasket are all good and fluid still comes out its prolly just a bad cap spring or rotted rubber causing ether a poor seal a low prussure release or just no seal at all

[Limited Z_400]

Originally posted by stichy85
find some sort of rubber stopper or something to make like a cork in place of your radiator cap. drill a hole in it just big enough to run a hose through it to go into the radaitor but make sure the hose seals off good . put it in place of radiator cap and run the hose into a clear bottle of water. run the engine and if it blows bubbles in the bottle of water you are getting combustion into the cooling system somehow


Did you try this? You can also try it by just by removin the cap (cold) with the level at the top and start the engine at idle. Rev it up a bit and observe for bubbles. Do not be confused with pump flow.

[dmann1]

i did try a known good cap i have two z's and took the cap off the other quad and it still blew coolant out. yes i can take the cap off when cold and it pushes coolant out like there is way to much pressure or flow coming from the cooling system

[dmann1]

well i finally got my z back together it turns out the head was warped enough to not let the head gskt to seal. put in a new piston while i had the head and cyl. off went to sandlake last week and it ran great without any problems :D

[twincat800]

I dont know how big i would make that smile after having to buy a new head! haha good info dmann

[dmann1]

well i didn't have to replace the head i had the machine shop resurface the old one alot cheaper then a new head!