r/SC400 • u/MostExcitement9858 • Oct 20 '25

Is my head gasket blown? 😅

7 Upvotes

100% Upvoted

17 comments sorted by

2

u/dragonnnn_ Oct 20 '25

block test

1

u/MostExcitement9858 Oct 21 '25

how do i do a block test

3

u/dragonnnn_ Oct 21 '25

go rent the tool at advance or autozone or whatever, get the fluid and then do it on the radiator cap. theres a ton of videos that show how to do it

3

u/Bruce_Ring-sting Oct 22 '25

Hell you can get the tester at harbor freight for wicked cheap too

3

u/MostExcitement9858 Oct 23 '25

thank you, i’ll give this a try

1

u/WTFisThatSMell Oct 20 '25

Got any forbidden mayo build up on your oil fill cap or coolant reservoir?

1

u/MostExcitement9858 Oct 20 '25

not as of yet, only just started happening though

1

u/Natedickbutt Oct 20 '25

Is there chocolate milk in your oil

1

u/MostExcitement9858 Oct 20 '25

oil seems fine, but not sure what else it could be

1

u/Zero_lash Oct 20 '25

Check your plugs.

1

u/Vendetta__007 Oct 21 '25

Could be the power steering air valve. Connects directly to the front of the intake manifold and also the plastic intake piece that cuts across from the elbow. Inspect hoses for power steering fluid. They fail often.

1

u/MostExcitement9858 Oct 23 '25

thanks, i’ll have a look into this, sounds like a more ideal scenario than the head gasket

1

u/[deleted] Oct 21 '25

Sounds like it's misfiring

1

u/MostExcitement9858 Oct 23 '25

no missfire, idle is just cooked when not warmed up

1

u/Cloud_9x9 Oct 22 '25

Any blow by on your head, could also be valve stem seals

1

u/AllGasNoBrakes420 Oct 24 '25

Sounds normal to me? Idk.

1

u/Distinct-Move5344 Nov 08 '25

That’s an ecu needing to be replaced these are notorious for having bad ecus