Hello,

 

My question is this.

 

Is there a certain mile interval in which head gaskets should be replaced even if they are not showing any symptoms of leaking etc?  I have heard some people say do it at 100k whether it needs it or not.

 

Thanks for any advise 

10 years or 100K miles. Whichever comes first. This means all the idlers also.

 

O.

Timing belt yes.

 

Head gaskets - no. Learn the symptoms to look for to spot it before it overheats. But get the full life from them. What year is your car?

10 years or 100K miles. Whichever comes first. This means all the idlers also.

 

O.

 maybe 9 years or 105K miles for timing belt system service, but headgaskets?

If you run synthetic, they will be leaking badly by 70-80k. If you run non-synthetic and extended drain intervals, they may never leak. But your engine will be done by 200k.

 

GD

Edited April 4, 20178 yr by GeneralDisorder

Timing belt yes.

 

Head gaskets - no. Learn the symptoms to look for to spot it before it overheats. But get the full life from them. What year is your car?

2006 with 99,370 on it

If you run synthetic, they will be leaking badly by 70-80k. If you run non-synthetic and extended drain intervals, they may never leak. But your engine will be done by 200k.

 

GD

GD, can you explain why this is? Why different oils cause such bigger issues?  

I don't know what oil was used in the past, so, I'm not sure what to use.

I have purchased all new Subaru parts for timing belt area, to include New Oil Pump (if the one that is on there has a 7 or 9 on the case), New Water Pump, Thermostat, all the idler & tensioner pulleys, coolant sensor, Thermostat and hoses and radiator...

2006 with 99,370 on it

 

 

way overdue for TB systems service if it hasn't been done.

way overdue for TB systems service if it hasn't been done.

I have been told from Subaru Master Tech it is 100,000 to 105,000

 

What are you thinking it should be?

I have been told from Subaru Master Tech it is 100,000 to 105,000

 

What are you thinking it should be?

 

the schedule in the OM has a time side as well. The TB system is 105K miles or 105 months, w'ever is first.  The toothed idler is often the weak spot, sometimes the tensioner of another idler. The grease goes bad and they seize or loose their bearings. Very rare it seems for the belt to break, unless caused by the chaos from a seized idler.

the schedule in the OM has a time side as well. The TB system is 105K miles or 105 months, w'ever is first.  The toothed idler is often the weak spot, sometimes the tensioner of another idler. The grease goes bad and they seize or loose their bearings. Very rare it seems for the belt to break, unless caused by the chaos from a seized idler.

Cool, thanks for the info.  What part of Texas are you in, if you don't mind me asking?

Non synthetic clogs everything up inside the engine. To include the oil control rings and piston skirt drain back holes. The sludge will also seal up the HG weeping. Synthetic just doesn't clog all the holes. So the gaskets leak sooner and heavier.

 

GD

Non synthetic clogs everything up inside the engine. To include the oil control rings and piston skirt drain back holes. The sludge will also seal up the HG weeping. Synthetic just doesn't clog all the holes. So the gaskets leak sooner and heavier.

 

GD

ok, I have no idea what oil is in it now... I wish I did..

Cool, thanks for the info.  What part of Texas are you in, if you don't mind me asking?

 

Living and working in Arlington for a while now - raised in Handley (east Ft.W)

Non synthetic clogs everything up inside the engine. To include the oil control rings and piston skirt drain back holes. The sludge will also seal up the HG weeping. Synthetic just doesn't clog all the holes. So the gaskets leak sooner and heavier.

 

GD

GD, what about using a "Synthetic Blend"? 

Remember that is just an opinion regarding synthetic oil.  It is an old wives tale that synthetic oil causes leaks.  It might reveal them.  However the best thing you can do for any car is use full synthetic from the start, and if it shows a leak, fix it.  I use nothing but synthetic on all of my engines, none of which is less than 120,000  miles, and they run great.  They had at least 50,000 when I started putting it in.

I don't know anything about synthetic blend. Sounds like some kind of marketing gimmick to me. I can't see a reason for having any amount of non synthetic mixed in with the good stuff.

 

GD

the main complaint I read about the blends is, you don't know if they are 50% synth, or 1% .

 

maybe you could discover over at www.bobistheoilguy.com . LOTS of info and discussions about oil over there.

I haven't found synthetic to "cause" leaks. The switchover process (flushing chems), or just the better quality of detergents and additives used in synthetic, cause it to break up sludge and varnish that is clogging up the holes already in your gaskets. 

 

I dragged a 1986 Chevy 305 small block out of the woods where it had sat for 11 years. 155k on it. I changed the valve cover gaskets, and did the timing chain and oil pan gasket. It's running full synthetic 10w40 Amsoil and doesn't leak or burn oil at all. It also has 185 to 190 compression on all 8 cylinders. It's all about how the stuff is maintained. I am quite sure that engine never saw synthetic once in it's former life as it was parked in 2005 due to a bad water pump. But being in a Trans Am it was well maintained . I ABUSE that poor 305 daily (why not it's worthless), and it has 40 psi hot idle oil pressure. It will probably last long after I'm tired of it's mediocre performance and swap it for a 383. 

 

GD

Edited April 10, 20178 yr by GeneralDisorder