Hi Pennock members. I am new to this forum site and need assistance. I bought a 1988 Fiero GT that had been sitting for close to ten years. I noticed a coolant leak beneath the motor when the tow truck driver was pulling the car to load it on to the back of the tow truck. I didn't think much of it and thought it was probably just a bad hose. I have since replaced all of the hoses and poured coolant in the car. I noticed that there is a major leak coming down the flywheel. I am unable to locate the source of the leak. Any ideas or advice is surely appreciated.

Regards.

Not saying this is necessarily your problem, but the coolant crossover pipe located on the front of the engine (relative to the rest of the car) is known to eventually rust out. It's the black pipe going across the engine in this picture.

[This message has been edited by Patrick (edited 11-19-2021).]

Could be a rusted out freeze plug, a leaking lower intake manifold gasket, a bad heater hose coupling or hose itself, a leaking coolant pipe, crossover pipe or the hoses that couple that pipe to the water pump and coolant tube. Fill the cooling system (follow procedure) start the engine bring it to operating temperature and search with a light.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

It looks like it is leaking on the back side of the motor (facing the back of the car). Could this still be the pipe you are speaking of Patrick? If it is a freeze plug, then it looks as if I will have to remove the motor to get to it Dennis. Either way, I may just have to remove the motor.

quote Originally posted by hampig: It looks like it is leaking on the back side of the motor (facing the back of the car). Could this still be the pipe you are speaking of Patrick? If it is a freeze plug, then it looks as if I will have to remove the motor to get to it Dennis. Either way, I may just have to remove the motor.

You mean the trunk side? Its been a long while since I worked on a 2.8L but IIRC the end manifold bolts may go into the water jacket and if sealant wasn't used that could be the leak. If you wish to fix the leak you need to be more specific on the exact location. It could be something so simple as a water outlet gasket or cap.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by hampig: It looks like it is leaking on the back side of the motor (facing the back of the car). Could this still be the pipe you are speaking of Patrick?

As I earlier stated, the coolant crossover pipe goes across the front-facing side of the engine... so no, I doubt a leak originating from the rear-facing side of the engine would be coming from this pipe.

Make sure the small coolant lines that run to the throttle body aren't loose and/or leaking.

quote Originally posted by hampig: It looks like it is leaking on the back side of the motor (facing the back of the car). Could this still be the pipe you are speaking of Patrick? If it is a freeze plug, then it looks as if I will have to remove the motor to get to it Dennis. Either way, I may just have to remove the motor.

So if you are seeing coolant on the Trunk side of the engine, 'running down the flywheel,' it seems like there are 4 options:

1) As has been mentioned, the freeze out plugs hidden in the space between the bell housing and the engine block (in which case you are screwed)
2) The coolant lines and connections to and from the throttle body, indicated by the Blue arrows in the picture
3) The temperature gauge sensor on the Odd cylinder head, right below the Yellow arrow in picture, see also the Diagram
4) Head gasket leak in the general area





To investigate #1, remove the cover (4 screws) that looks like the final picture below and if it is leaking inside that area it seems you should be able to see a lot of fluid slung around.

To investigate #2 inspect the connections into the throttle body and also along the lines themselves to look for signs of holes

To investigate #3 unhook the sensor (you need to depress a tab in the clip I believe) and check around the threads for the leak

For #4 the leak would have to NOT be into a cylinder because that would create clouds of white smoke in the exhaust. A leak would have to be along the perimeter of the cylinder head, which might mean the head is warped and not sealing properly. Has anyone ever seen just a simple failure of the head gasket that leaks coolant down the outside of the engine and NOT also into the cylinder??



Caveat: this is all with respect to the 88 with a 5spd transmission. I don't know if having an automatic would change any of those options or introduce more ...

Thank you Notorio (as well as Patrick and Dennis). I believe you are correct and it is one of the freeze out plugs hidden in the space between the bell housing and the engine block. I will take your suggestion and check the other options. However, my gut is telling me that I will need to remove the engine, and if this is the case, I will be rebuilding both the motor and trans.

Thanks again guys.