Major coolant leak

[GEN 3 SHO FAN]

Hi guys,

Yesterday entering on highway, I decided to ask a little more hp to my engine (not WOT, but 60-70% of it) after some seconds, I detected a bad smell of coolant and remarked that my heat needle was going up...

I parked the at the first exit and turn off the engine ASAP. What I found under the hood is an empty coolant tank and spread coolant all over the area. Mostly on the belt side of the engine.

This let me thing about a blown head gasket... (Compression going into coolant system and push out all the coolant.)

Since some time, when I was doing acceleration with the car, the low coolant light goes on but, once the car aside the road, all was normal (coolant at the same level as it was).

Is others issues can cause this kind of things ?? A broken hose for example or the infamous "Y" made from plastic in this area... I was projecting to replace it.

If its a blown head gasket, I'm not sure I will repair it as the car need some other repairs (body jobs, windsheild and so on).

(The car has no big upgrades and has now 155k.)

Thanks for your advices,

 

[luigisho]

You're going to have to pressure test the radiator and hoses. There is a big coolant hose that runs under the front of the car to check. I've had to fix most of it (including the small plastic Y with a metal one). I agree with HG assessment. IF that then dump it.

 

[99sho-time]

i doubt it's a hg with the reverse cooling. these things once one hose blows it's time for a coolant hose overhaul

 

[GEN 3 SHO FAN]

My mechanic has the same opinion too and in fact, the engine still turning smooth (regular rpm). I forgot to check if white smoke at the rear however.

Anyway, I towed the car to the house last night and put it in the garage for further investigations.

I made some tests. I filled the coolant bottle with engine off. At the moment where the water appoach the top of the bottle, water begin to leak from the bottom of the "V" somewhere under the fuel lines and fall at each end of the engine. The rad is dry at each end and the big hose was already "revised" to be safer.

That let me think about 2 possibles problems.

1) The famous "Y" and the small hoses there are toasted somewhere. (Even if the visible part of the Y seems ok.)

2) On the driver side under the fuel line, there is a big coolant hose going there ending with an aluminium part bolted to the engine. There is a gasket between these parts and someone in the last years had a problem with this gasket. (Is that you 99sho-time ?) IIRC, this gasket isn't available anywhere... (SHO 96-99 unique)

 

[luigisho]

Yep time to dig and replace. Have you done the Y before? Not too bad except I had to pull mine out in pieces.

 

[GEN 3 SHO FAN]

No. I was projecting doing the Y this spring but I finnally reported the job... :S I will do it even if isn't the problem at the same time.

I found the post I spoke of.

Leaking Freeze plug?

Got it all back together and i got coolant spraying out the back of the bellhousing. The heater core hoses are new and dont appear to be leaking. The 2 hoses in the middle of the motor look dry too so that only leaves one thing:bs: . Has anybody ever had leaking freeze plugs? This...

shoforum.com

It could be part # 8590 (metal gasket on driver side) but its most probably one of the hoses of the Y according to what I saw when I turn off the hot engine (coolant all over the passenger side of the engine).

 

[99sho-time]

I have and you can do it by taking the power steering pump off. Ive done all the hoses except the heater core lines.

 

[GEN 3 SHO FAN]

Long story short, I will take the "long way" because I messed up with a wrong MAF and I must change all the rear spark plugs too (they are probably black). And IIRC you spoke about a part that accumulating oil (rectangular one between knock sensors) that I will try to clean by the way.

Where is the heater core on this engine I never saw it...? Into the "V" I presume. I know I have one, all canadians SHO have one.

 

[99sho-time]

Heater core is in the fire wall in the center goes into the dashboard. the hoses run from the engine and plug into the firewall. The oil separator box yes. you could try and remove it i'd say it's worth it just clean the gaskets up and coat them with the permatex tacky gasket coating. not the copper one

 

[GEN 3 SHO FAN]

Sorry, I mistaken with the bloc heater... :S

 

[Qshiplvr]

No. I was projecting doing the Y this spring but I finnally reported the job... :S I will do it even if isn't the problem at the same time.

I found the post I spoke of.

Leaking Freeze plug?

Got it all back together and i got coolant spraying out the back of the bellhousing. The heater core hoses are new and dont appear to be leaking. The 2 hoses in the middle of the motor look dry too so that only leaves one thing:bs: . Has anybody ever had leaking freeze plugs? This...

shoforum.com

It could be part # 8590 (metal gasket on driver side) but its most probably one of the hoses of the Y according to what I saw when I turn off the hot engine (coolant all over the passenger side of the engine).

GEN 3 SHO FAN: I posted the step-by-step pics of my cam weld teardown, which gives you a very good picture story to get to the "Y" that is failing. Here is the link:

Gen3 V8 SHO engine disassembly for cam weld - pictures

What follows is my documenting the disassembly of my Gen3 ‘99 SHO motor for cam welding back in 2016. Since I’m not the mechanic doing all the hard work (JohntheSHOguy is), my descriptions may not be entirely accurate, but the SEQUENCE of photos should be accurate. First, need to take off the...

shoforum.com

 

[GEN 3 SHO FAN]

It's a little bit too late but thanks. All is rebolted since 2 months. I have some data already on this subject. The only thing was the PCV hoses, all felt apart and I have to replace all the hose to the valve... /$!"$"%