Sounds like exhaust tick, but it's not

[Sixlitre]

Before I put Mustang shorties on my 90' (5.0 litre)

I had an annoying exhaust tick, tick, tick that I was sure was the manifold gasket. I used Mr.Gasket manifold/header gaskets and torqued and re-torqued the headers.

Thought the Y-pipe wasn't sealing on the header ball, so I torqued the $h!t out of those bolts, that wasn't it.

The annoying thing is it made the sound before and after the header install.

I was thinking maybe the AIR pipes that go into the back of the heads ?

Or maybe the 4 way thermactor valve that controls the air from the air pump ?

I've never seen a back fire valve on these 5.0 litres, where would it be installed ?

It only happens under load. Once you're cruising, or at idle, you don't notice the tack, tack, tack at all.

It makes an otherwise smart looking Lincoln sound like a real beater. All suggestions welcome guys

Sixlitre

[Chevyguy]

The Thermactor tubes on the back of the heads are a likely source of leakage. I broke the tube after my 3rd or 4th removal of the H pipe on my 90 Stang. Any EFI 5.0 has the same tube, I got one from a Box Grand Marq it fit the HO stang just ducky.

[dickwells]

You can usually pin down this kind of leak by putting some kind of Throttle body cleaner through it to make it smoke and then note where the smoke comes out.

[gadget73]

+1 on the thermactor pipe being rotted out.

[Sixlitre]

Thanks guys

well this is all good news, three votes for the crossover pipe between the heads. Sure makes it sound like a "beater du joure".

Guess I'm gonna have to get my woolies on as temperatures are dropping like a stone over the next week. Should be -38 sometime Friday !!!!!!!!!!!!! Off to the junkyards.

My parts guy at the Stealership told me to look for 89',90' and 91' CVs or GMs, but cautioned me the earlier years had different numbers.

Do you think 88' and earlier might do the trick regardless ?

Much obliged, and I will be trying that throttle body cleaner trick Dick.

Sixlitre

[Sixlitre]

To answer my own question

I found the pipe on the Advance website, then hit the button (what other vehicles does this fit). Up came;

85-91 LTD/CV
85-90 GM
85-90 TC
85-88 T-Bird & Cougar (though not the Gatineau Cougar {grin})
83-95 Mustang

Standard part # AT127
Niehoff # FE4210
BWD # EC4210

NAPA CRB 21127

The cheapest being $49.00 (Niehoff), but I'll probably still hit the yards as I need a thermactor valve and some other stuff too.

Thanks for the help

Sixlitre

[Chevyguy]

$49.00 approaches the get new vs freeze ass off threshold.

The Thermactor valve don't like coming off fur sho. So some -30°C wrenching may be in ur future.

[gadget73]

86-91 5.0 powered cars are the same. 85 is different, the CFI cars had the inlet at a different angle, which would directly interfere with the upper intake manifold. All the SEFI motors had the same part tho.

[Sixlitre]

$49.00 approaches the get new vs freeze ass off threshold.

The Thermactor valve don't like coming off fur sho. So some -30°C wrenching may be in ur future.

You said it !

I'll probably "pays the money" for new, if that's it. It's so f-f-f-f-freapin' cold out there today I decided to let the exhaust leak until it warms up hopefully Monday.

It's -29 (-36 w/windchill) today, -27 tomorrow and -32 Friday !!!!!!!!!!

Went out to plug in one of the Cheeselers and the Lincoln is leaking anti-freeze under the front grill ! I KNOW the mixture is correct, so it must have pushed past a hose clamp or something.

Last week it was leaking ATF from the same spot ! That was just the cooler hose clamp having slacked off.

There's a new rad and heater core so I hope it's a hose clamp and not the dreaded pushed out frost plug !!!!!!!!!!!!!!!!!!!!!!!!!!!!!

The Bronco's got a REAL coolant leak right now and I'm trying to track that down too.

Sixlitre

p.s./
Thanks for the FYI Gadget. They've got the pipe in stock, so I'm going to make good and sure I need it and remove mine and take it in with me to compare. It had better come with the pipe to head gaskets