| Author | Message | ||
     Ed Mckinley Unregistered guest Posted From: 67.173.154.161 |
After completing a number of repairs on my 89 Corniche 29169, the last being new seals on the hydraulic pumps I put everything back together only to now find coolant leaking under the intake manifold. I cannot see where it is coming from but does seem to be originating on the left side towards the front. Has anyone had experience with this before? Any guidance would be most appreciated. My next step it would seem is to remove the injection unit and intake manifold to have a better look (Message approved by david_gore) | ||
| Brian Vogel Prolific User Username: guyslp Post Number: 227 Registered: 6-2009 |
Ed, If possible, could you post photographs of where the coolant pool actually is and the area where you suspect it's coming from? In this, as in many instances, a lot of territory can be covered with those pictures. Also, someone who's "been there, done that" might be able to see something that others don't. Brian P.S. This forum only accepts pictures with a maximum dimension of 640x480 pixels, and it cares about having "landscape" orientation (that is, you can't post a 480x640 photo). | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2765 Registered: 4-2003 |
I have never seen a leak there before, but the inlet manifold gaskets seal the coolant passages between the heads and the manifold. If the inlet manifold has been removed at some stage there are always the possibilities of poor reassembly or reused gaskets. You may try checking the manifold bolts for tightness. Removing the inlet manifold on an SY with carburettors is surprisingly not at all a big job in the worst case. After undoing the fuel pipework and linkages, a single bolt releases the carburettor assembly. After that, the manifold drain pipe is just a little fiddly but the 16 manifold retaining bolts are completely accessible. RT. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 952 Registered: 6-2006 |
However , on an `89 car things are a bit more complicated ! The coolant system also has a number of o rings that garden and can and do leak . I would wash the engine down to remove existing stains ,then let it dry off completely. if no coolant is apparent run it and watch while it warms up . obviously if you have a coolantsystem pressure tester , you can use that once the engine is dry. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2766 Registered: 4-2003 |
Paul, I do stand corrected. For some reason I thought this was a Silver Shadow subject. Indeed fuel injection makes the task far more onerous warranting better diagnosis beforehand as you explained. RT. | ||
| Bill Coburn Moderator Username: bill_coburn Post Number: 1478 Registered: 4-2003 |
I am always delighted when Richard gets confused - a state I enjoy permanently. My meanderings around an '89 Turbo recalls a casting under the thermostat housing that housed a number of sensors the one begging my interest being the sender for the temp gauge. The others were typically an advisory medium to alert the driver to any religious ceremonies that should be attended to that day and whether the cap on the fuel filter was indeed fully closed!! My God - give me a crank handle and a fistful of burning waste cotton and Ill start the pig of a thing etc!! Having just been introduced to the practice of force feeding brandy Alexanders I feel I don't need my pills to night. Get a grip of yourself lad! The only leakage points I can think of are the joints at the sensors mentioned or the intake manifold/head interfaces may be leaking. But wait, I think those manifolds have one or two drain plugs in the cooling passages on the underside and they have been known to corrode out. You should borrow a remote camera wand linked to your lap top and have a look. Also check the electrical charge differential between your coolant and earth. If it is more than point nine of a volt, you have a major corrosion problem. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 954 Registered: 6-2006 |
Bill, go for a B52 . . .sounds like they may do the trick and probably up your street. ;) The thermostat housing is the separate type with the o'rings and pipes connecting them to the head cooling galleries. So unfortunately plenty of places and they don't like being disturbed. Always get a set of new o'rings before touching them to avoid tears after putting them back together.  | ||
| Ed Mckinley Unregistered guest Posted From: 67.173.154.161 |
after removing some of the jungle of hoses, etc it appears that the hard pipe joint which sits on top of the left side inlet manifold is my problem. This pipe eventually makes its way back to the thermostat housing. It is leaking at the bottom of the joint and the coolant is running down into the valley and then back over the bell housing and onto the "Y" connection on the exhaust. Is this a typical failure point? I am assuming that replacement of all the O rings is probably advised? (Message approved by david_gore) | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2767 Registered: 4-2003 |
This is quite rare but promises a rewarding repair. It is most likely that someone has used o-rings of Buna-N (Nitrile) material in the past as that is the material used on the vast majority of o-rings. See the compatability chart in the Technical Library. Nitrile is incompatible with coolant. Do make sure that the o-rings you use are genuine ones made from EPDM. They may cost a few cents more than generic EPDM o-rings but it is safer that way. RT. | ||
| Edward Mckinley Yet to post message Username: ed_mckinley Post Number: 1 Registered: 2-2013 |
The culprit has been found and fixed. The "O" ring seal on the hard piped coolant return which sits above the intake manifold making its way back to the thermostat housing was the problem. I replaced four of them for good measure.  |
