A few concerning issues?

[rx7pat]

Hi guys well after having a few coolant issues I decided to pull the engine out and change the seals. A fter inspecting the housing all looked pretty good condition. The water seals in the engine fell apart when I took it apart, which is prob normal I would imagine.
 
Anyway changed a few bits like bearings and put nice new uprated water seals in from pineapple racing. Finally the engine is back together and running pretty smooth. But.... I am still having some coolant issues the main concern is that the coolant hoses become presurised as the engine gets up to temprature. Also there is a very minor amount of steam leaking somewhere under the std intercooler??
 
Anyone have any ideas? I have put a few pics below
 

[rx7pat]

[rx7pat]

[BlitzBoy]

Did you check the plates for warpage when you did the rebuild?. Your original water seals probably didnt fail, if a front plate is warped it will let combustion gases into the waterways

[rx7pat]

I did check each one they where within tollerances. Could it be anything else? The bubble tank doesnt overflow with boiling water or anything its just the main coolant pipes become hard. should they do this normally when engine is warm??
thanks

[fil_auto]

I am by no means a rotary guru.... but seeing as they become pressurised.... you\'d expect them to become hard surely?!:2Confused:rolleyes:

I did check each one they where within tollerances. Could it be anything else? The bubble tank doesnt overflow with boiling water or anything its just the main coolant pipes become hard. should they do this normally when engine is warm??
thanks

[Prof]

That blue silicon pipe that feeds hot water through the throttle body and then into the bac valve and back to the water pump - it will swell and could split - your \'steam\' coming from underneath the intercooler could be down to that.
 
For water carrying pipes, you need to use the reinforced silcon hose - they don\'t do that small enough for the 8mm water feeds.

[rx7pat]

It is pretty thick samco piping. The main coolant pipes Do become hard and pressurised. Is that normal when the engine is hot?? Also cant see any mayo in the coolant or oil neck.
 

[Prof]

They shouldn\'t get too hard - the top one should have some give in it - but should be cold on initial starting of the engine, and will get warm (after about 5-10 mins) when the wax pellet thermostat valve opens up.
 
Does sound like they are pressurizing.

[Prof]

It is pretty thick samco piping. The main coolant pipes Do become hard and pressurised. Is that normal when the engine is hot?? Also cant see any mayo in the coolant or oil neck.
 

They look pretty beefy - should be ok with them then.  The only 8mm stuff I found was way to thin for hot water to be in them.

[rx7pat]

Thanks for the help, sounds like the rebuild didnt work. have to wait till I got some money and get a garage to have a look.

[Brett]

Are you getting champagne bubbles in the water when the engine is running?

[rx7pat]

no bubbles although the level rises and falls if that makes sence.

[kimducati]

If you\'re worried, get your local garage to do a \'sniff\' test on the water, to see if there\'s any combustion gas mixed in.
Only cost a few pounds and then you\'ll know for sure.
 
Kim.
 
p.s. that isn\'t sticking your hooter into the expansion tank BTW. Some kind of chemical analysis, similar to litmus paper.

[oldrotary]

Like you I rebuilt my engine last year due to coolant issues. The most obvious change since then is that when the engine is started from cold now the top hose remain soft unpressurised and easy to squeeze.
Before the rebuild there was obviously a slight leak in the coolant system allowing the pressure to build up almost as soon as the engine was started. The pressure did not  build up to such a level as to blow any significant amount of coolant out of the system, but often when checking the coolant there had been a very small transfer of fluid into the overflow bottle. On rare occasions on long  journeys , sufficient coolant was blown into the overflow bottle to cause the coolant level buzzer to sound. All that was then necessary was to stop release the pressure from the system and then transfer the coolant back into the system. This happened about four times in a year.
I therefore think that checking for pressure in the top hose is a very good indication of the effectiveness of the engine seals.
Under normal cold start conditions the coolant temperature will rise as the engine warms up. When approximately 83C is reached the thermostat will open and the coolant will pass to the radiator and return cooled to the engine maintaining a reasonable operating temperature. The top hose should still remain unpressurised and easy to squeeze by hand.
The top hose should only become pressurised once the atmospheric boilng temperature of the coolant is reached. Now normal antifreeze will raise the boiling point of the coolant to about 106C dependant on antifreeze ratio. On a fast run or when the coolant system is inadequate then this temperature could be exceeded. Under these circumstances the pressure in the system will be raised as the coolant tries to  boil, this pressure is limited by the radiator pressure cap. This increased pressure further raises the boiling point up to about 125-130C (dependant on the radiator cap setting and coolant mixture). Thus the top hose should remain unpressurised untill the coolant temperature reaches about 106C, at this point it will start to increase in pressure untill about 130C at which point the radiator cap will open to release the pressure and allow the coolant to pass into the overflow tank.
 
If the seals are leaking this pressurisation will occur at normal running temperatures due to just a tiny leak of high pressure gas from the combustion process entering the coolant system and the top hose will be hard to squeeze. So if your coolant temperature is below 106c and the top hose is hard to squeeze then this does suggest an engine seal leak.